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2020 Volume 31 Issue 2
2020, 31(2): 307-310
doi: 10.1016/j.cclet.2019.04.063
Abstract:
The synthesis of α-ZrP with a range of crystallinity is of high importance due to the different requirements in various applications. Nanosized crystalline α-ZrP is typically obtained by refluxing amorphous ZrP in concentrated H3PO4 solutions. Microcrystalline α-ZrP are obtained by direct precipitation in the presence of either HF or oxalic acid which are used as complexing agents for zirconium. These larger crystals are useful as ion-exchangers in column-type applications as the back pressure can be significantly reduced. A novel minimalistic synthesis that is green, simple and fast is highlighted in this review. Both nano-sized and micro-sized α-ZrP can be prepared via this protocol to meet many potential applications. Applications of α-ZrP in ion-exchange, catalysis, lubricants, intercalation hosts, polymer fillers and fire retardants are discussed.
The synthesis of α-ZrP with a range of crystallinity is of high importance due to the different requirements in various applications. Nanosized crystalline α-ZrP is typically obtained by refluxing amorphous ZrP in concentrated H3PO4 solutions. Microcrystalline α-ZrP are obtained by direct precipitation in the presence of either HF or oxalic acid which are used as complexing agents for zirconium. These larger crystals are useful as ion-exchangers in column-type applications as the back pressure can be significantly reduced. A novel minimalistic synthesis that is green, simple and fast is highlighted in this review. Both nano-sized and micro-sized α-ZrP can be prepared via this protocol to meet many potential applications. Applications of α-ZrP in ion-exchange, catalysis, lubricants, intercalation hosts, polymer fillers and fire retardants are discussed.
2020, 31(2): 311-323
doi: 10.1016/j.cclet.2019.07.015
Abstract:
Enantiomerically pure 2-substituted indolines are an important class of nitrogen heterocycles that occur frequently in many alkaloid natural products and biologically active compounds. Consequently, the synthesis of such skeletons is of great significance. The past years have witnessed a number of remarkable advances in the development of efficient strategies to construct this class of chiral compounds. This review summarizes the recent advances in asymmetric synthesis of 2-substituted indoline derivatives. Due to the limitation of the length, this review only summarizes those works published from January of 2012 to January of 2019. Meanwhile, methods towards synthesis of fused and spirocyclic indolines will not be discussed in this review.
Enantiomerically pure 2-substituted indolines are an important class of nitrogen heterocycles that occur frequently in many alkaloid natural products and biologically active compounds. Consequently, the synthesis of such skeletons is of great significance. The past years have witnessed a number of remarkable advances in the development of efficient strategies to construct this class of chiral compounds. This review summarizes the recent advances in asymmetric synthesis of 2-substituted indoline derivatives. Due to the limitation of the length, this review only summarizes those works published from January of 2012 to January of 2019. Meanwhile, methods towards synthesis of fused and spirocyclic indolines will not be discussed in this review.
2020, 31(2): 324-328
doi: 10.1016/j.cclet.2019.05.060
Abstract:
An enantioselective carboxylative cyclization of propargylic alcohols and CO2 was realized under mild conditions, based on a kinetic resolution strategy, which enabled the synthesis of chiral cyclic carbonates and propargylic alcohols with promising yield and enantioselectivity simultaneously.
An enantioselective carboxylative cyclization of propargylic alcohols and CO2 was realized under mild conditions, based on a kinetic resolution strategy, which enabled the synthesis of chiral cyclic carbonates and propargylic alcohols with promising yield and enantioselectivity simultaneously.
2020, 31(2): 329-332
doi: 10.1016/j.cclet.2019.05.053
Abstract:
A divergent intramolecular reaction of phosphine tethered alkyne in protic solvent was developed. This provided a novel and simple access to a large variety of (Z)-alkenylphosphine oxides and phospholane oxides. Our preliminary studies suggested that these divergent reactions are closely related to the reaction condition and molecular structure. A possible mechanism of C-P bond cleavage of a pentacoordinated hydroxyphosphorane intermediate was proposed.
A divergent intramolecular reaction of phosphine tethered alkyne in protic solvent was developed. This provided a novel and simple access to a large variety of (Z)-alkenylphosphine oxides and phospholane oxides. Our preliminary studies suggested that these divergent reactions are closely related to the reaction condition and molecular structure. A possible mechanism of C-P bond cleavage of a pentacoordinated hydroxyphosphorane intermediate was proposed.
2020, 31(2): 333-336
doi: 10.1016/j.cclet.2019.06.007
Abstract:
The acetyl ester plays an important role for protection of the hydroxyl groups in carbohydrates synthesis. In the present study, we described an efficient deprotection of acetyl group of pentacyclic triterpenoid by using methanolic ammonia in THF solution. Good selectivity for cleaving gal-C2-OAc group of 3β-hydroxy-olean-12-en-28-oic acid 28-N-2, 3, 4, 6-tetra-O-acetyl-β-D-galactopyranoside (3) was achieved in the presence of methanolic ammonia within 4 h at low temperature (-60℃) in a yield of 56%. The reaction disclosed here provides a new method for the synthesis of C2 selective modified carbohydrates, which is more useful than conventional synthesis procedure that usually requires many steps including temporary regioselective protection and deprotection. When the reaction temperature was increased from -60℃ to room temperature, the cleavage of the other three acetyl groups of galactose in an order of C4-OAc > C3-OAc > C6-OAc was observed. Based on this study, a plausible route for the deacetylation reaction has been proposed.
The acetyl ester plays an important role for protection of the hydroxyl groups in carbohydrates synthesis. In the present study, we described an efficient deprotection of acetyl group of pentacyclic triterpenoid by using methanolic ammonia in THF solution. Good selectivity for cleaving gal-C2-OAc group of 3β-hydroxy-olean-12-en-28-oic acid 28-N-2, 3, 4, 6-tetra-O-acetyl-β-D-galactopyranoside (3) was achieved in the presence of methanolic ammonia within 4 h at low temperature (-60℃) in a yield of 56%. The reaction disclosed here provides a new method for the synthesis of C2 selective modified carbohydrates, which is more useful than conventional synthesis procedure that usually requires many steps including temporary regioselective protection and deprotection. When the reaction temperature was increased from -60℃ to room temperature, the cleavage of the other three acetyl groups of galactose in an order of C4-OAc > C3-OAc > C6-OAc was observed. Based on this study, a plausible route for the deacetylation reaction has been proposed.
2020, 31(2): 337-340
doi: 10.1016/j.cclet.2019.06.008
Abstract:
A new method for the synthesis of 3-thioazaspiro[4,5]trienones was developed using Pd nanoparticle catalysts, which are highly efficient, environmentally friendly and recyclable. Alkynes and thiophene phenols are effectively cyclized by Pd/ZrO2 catalyst under visible light irradiation. The present protocol simply utilizes visible light as the safe and ecofriendly energy source, and the Pd/ZrO2 nanocomposite as photocatalyst provides a simple and practical approach to various 3-thioazaspiro[4,5]trienones in moderate conditions to high yields
A new method for the synthesis of 3-thioazaspiro[4,5]trienones was developed using Pd nanoparticle catalysts, which are highly efficient, environmentally friendly and recyclable. Alkynes and thiophene phenols are effectively cyclized by Pd/ZrO2 catalyst under visible light irradiation. The present protocol simply utilizes visible light as the safe and ecofriendly energy source, and the Pd/ZrO2 nanocomposite as photocatalyst provides a simple and practical approach to various 3-thioazaspiro[4,5]trienones in moderate conditions to high yields
2020, 31(2): 341-344
doi: 10.1016/j.cclet.2019.06.030
Abstract:
Organocatalysis represents a promising field in chemical fixation of CO2. Herein, a facile metal-free strategy was reported for the one-pot preparation of cyclic carbonates and α-hydroxy ketones from vicinal diols, propargylic alcohols and CO2. Wide scope of vicinal diols and propargylic alcohols was demonstrated to be efficient under the DBU-catalyzed conditions. A plausible mechanism was proposed, which included detailed main and side reactions under the metal-free conditions.
Organocatalysis represents a promising field in chemical fixation of CO2. Herein, a facile metal-free strategy was reported for the one-pot preparation of cyclic carbonates and α-hydroxy ketones from vicinal diols, propargylic alcohols and CO2. Wide scope of vicinal diols and propargylic alcohols was demonstrated to be efficient under the DBU-catalyzed conditions. A plausible mechanism was proposed, which included detailed main and side reactions under the metal-free conditions.
2020, 31(2): 345-348
doi: 10.1016/j.cclet.2019.06.031
Abstract:
In this study, various nonionic surfactants (NS) with different ethylene oxide (EO) numbers and tail lengths and its binary blends with anionic surfactants (AS) were used as emulsifiers for naphthenic oil to form the microemulsion metalworking fluids (MWFs), and the effects of them on the stability of the emulsion system were investigated by formulation triangle method. The results indicated that binary complex surfactants of NS and AS as emulsifiers exhibited better emulsifying effect than that of single NS. NS with different EO numbers and tail lengths presented various emulsifying effects. NS (EO = 10) exhibited the greatest number of stable formulations, especially the TX-10, but no linear relationship existed between the number of stable formulations and the tail length of NS. In addition, aromatic primary alcohol ethoxylate (APAE) series surfactants containing benzene groups similar to the cycloalkanes in the naphthenic oil so that presented the best emulsifying affect and the greatest number of stable formulations. The co-surfactant of sodium dodecyl benzene sulfonate (SDBS) binary blends with NS exerted the best synergistic effect, and the stable formulations numbers were ranged from 5 to 7, next sodium stearate (SS) comes last followed by sodium dodecyl sulfate (SDS-1) and sodium dodecyl sulfonate (SDS-2).
In this study, various nonionic surfactants (NS) with different ethylene oxide (EO) numbers and tail lengths and its binary blends with anionic surfactants (AS) were used as emulsifiers for naphthenic oil to form the microemulsion metalworking fluids (MWFs), and the effects of them on the stability of the emulsion system were investigated by formulation triangle method. The results indicated that binary complex surfactants of NS and AS as emulsifiers exhibited better emulsifying effect than that of single NS. NS with different EO numbers and tail lengths presented various emulsifying effects. NS (EO = 10) exhibited the greatest number of stable formulations, especially the TX-10, but no linear relationship existed between the number of stable formulations and the tail length of NS. In addition, aromatic primary alcohol ethoxylate (APAE) series surfactants containing benzene groups similar to the cycloalkanes in the naphthenic oil so that presented the best emulsifying affect and the greatest number of stable formulations. The co-surfactant of sodium dodecyl benzene sulfonate (SDBS) binary blends with NS exerted the best synergistic effect, and the stable formulations numbers were ranged from 5 to 7, next sodium stearate (SS) comes last followed by sodium dodecyl sulfate (SDS-1) and sodium dodecyl sulfonate (SDS-2).
2020, 31(2): 349-352
doi: 10.1016/j.cclet.2019.07.019
Abstract:
The isoindolinone and biaryl scaffolds are prevalent in natural products and drug molecules, which have showed broad and interesting biological activities. The efficient construction of such hybridized molecules and biological evaluation are of great interest to medicinal chemistry community. In this communication, we report an efficient Brønsted acid-promoted C(sp3)-H functionalization approach that enables the rapid construction of biologically important isoindolinone/[1,2,4]triazolo[1, 5-a]pyrimidine hybrids from 5-methyl-7-(2, 4, 6-trimethoxyphenyl)-[1,2,4]triazolo[1, 5-a]pyrimidine, 2-formylbenzoic acid and various anilines. The title compounds were generated in high to excellent yields (up to 96%) regardless of the electronic nature and steric effects of the substituents. In this reaction, an isoindolinone scaffold, one C-C single bond, and two C-N bonds were formed simultaneously with high atom economy. In this work, we have envisioned that the methyl group linked to the electron-deficient Nheterocycles could be used as a new synthetic handle for late-state diversification and may have broad applications in the field of organic and medicinal chemistry. Besides, the title compounds have exhibited promising activity against the SKP2-CKS1 interaction.
The isoindolinone and biaryl scaffolds are prevalent in natural products and drug molecules, which have showed broad and interesting biological activities. The efficient construction of such hybridized molecules and biological evaluation are of great interest to medicinal chemistry community. In this communication, we report an efficient Brønsted acid-promoted C(sp3)-H functionalization approach that enables the rapid construction of biologically important isoindolinone/[1,2,4]triazolo[1, 5-a]pyrimidine hybrids from 5-methyl-7-(2, 4, 6-trimethoxyphenyl)-[1,2,4]triazolo[1, 5-a]pyrimidine, 2-formylbenzoic acid and various anilines. The title compounds were generated in high to excellent yields (up to 96%) regardless of the electronic nature and steric effects of the substituents. In this reaction, an isoindolinone scaffold, one C-C single bond, and two C-N bonds were formed simultaneously with high atom economy. In this work, we have envisioned that the methyl group linked to the electron-deficient Nheterocycles could be used as a new synthetic handle for late-state diversification and may have broad applications in the field of organic and medicinal chemistry. Besides, the title compounds have exhibited promising activity against the SKP2-CKS1 interaction.
2020, 31(2): 353-356
doi: 10.1016/j.cclet.2019.07.029
Abstract:
A new star-shaped molecule StOF-Br3 containing oligofluorenes and halogen atoms (Bromine) has been synthesized and studied by Scanning Tunneling Microscopy (STM) at the highly oriented pyrolytic graphite (HOPG) surface. We have obtained the high-resolution self-assembled STM images, from which the highly ordered and closely packed non-porous arrangements of the StOF-Br3 molecular selfassemblies at the heptanoic acid/HOPG surface could be observed. The molecular models and selfassembled StOF-Br3 architectures have been given in the following text. Besides, we have also figured out the surface free energy by the density functional theory (DFT) calculation, which proved that the halogen…halogen interaction was strong enough to stabilize the ordered molecular self-assemblies. This work verifies the existence of bromine…bromine interactions, and meanwhile provides a kind of effective approach for quickly building ordered molecular nanoarchitectures with large areas and different geometries.
A new star-shaped molecule StOF-Br3 containing oligofluorenes and halogen atoms (Bromine) has been synthesized and studied by Scanning Tunneling Microscopy (STM) at the highly oriented pyrolytic graphite (HOPG) surface. We have obtained the high-resolution self-assembled STM images, from which the highly ordered and closely packed non-porous arrangements of the StOF-Br3 molecular selfassemblies at the heptanoic acid/HOPG surface could be observed. The molecular models and selfassembled StOF-Br3 architectures have been given in the following text. Besides, we have also figured out the surface free energy by the density functional theory (DFT) calculation, which proved that the halogen…halogen interaction was strong enough to stabilize the ordered molecular self-assemblies. This work verifies the existence of bromine…bromine interactions, and meanwhile provides a kind of effective approach for quickly building ordered molecular nanoarchitectures with large areas and different geometries.
2020, 31(2): 357-360
doi: 10.1016/j.cclet.2019.07.031
Abstract:
A range of bench-stable carbazole-containing hypervalent iodine(Ⅲ) reagents were synthesized by I-N bond formation in good yields. This kind of benziodoxolone reagents was used for a C-N coupling reaction to introduce a carbazole group to aromatic heterocycle compounds.
A range of bench-stable carbazole-containing hypervalent iodine(Ⅲ) reagents were synthesized by I-N bond formation in good yields. This kind of benziodoxolone reagents was used for a C-N coupling reaction to introduce a carbazole group to aromatic heterocycle compounds.
2020, 31(2): 570-574
doi: 10.1016/j.cclet.2019.04.047
Abstract:
Volume expansion and polysulfide shuttle effect are the main barriers for the commercialization of lithium-sulfur (Li-S) battery. In this work, we in-situ polymerized a cross-linked binder in sulfur cathode to solve the aforementioned problems using a facile method under mild conditions. Polycarbonate diol (PCDL), triethanolamine (TEA) and hexamethylene diisocyanate (HDI) were chosen as precursors to prepare the cross-linked binder. The in-situ polymerized binder (PTH) builds a strong network in sulfur cathode, which could restrain the volume expansion of sulfur. Moreover, by adopting functional groups of oxygen atoms and nitrogen atoms, the binder could effectively facilitate transportation of Li-ion and adsorb polysulfide chemically. The Li-S battery with bare sulfur and carbon/sulfur composite cathodes and cross-linked PTH binder displays much better electrochemical performance than that of the battery with PVDF. The PTH-bare S cathode with a mass loading of 5.97 mg/cm2 could deliver a capacity of 733.3 mAh/g at 0.2 C, and remained 585.5 mAh/g after 100 cycles. This in-situ polymerized binder is proved to be quite effective on restraining the volume expansion and suppressing polysulfide shuttle effect, then improving the electrochemical performance of Li-S battery.
Volume expansion and polysulfide shuttle effect are the main barriers for the commercialization of lithium-sulfur (Li-S) battery. In this work, we in-situ polymerized a cross-linked binder in sulfur cathode to solve the aforementioned problems using a facile method under mild conditions. Polycarbonate diol (PCDL), triethanolamine (TEA) and hexamethylene diisocyanate (HDI) were chosen as precursors to prepare the cross-linked binder. The in-situ polymerized binder (PTH) builds a strong network in sulfur cathode, which could restrain the volume expansion of sulfur. Moreover, by adopting functional groups of oxygen atoms and nitrogen atoms, the binder could effectively facilitate transportation of Li-ion and adsorb polysulfide chemically. The Li-S battery with bare sulfur and carbon/sulfur composite cathodes and cross-linked PTH binder displays much better electrochemical performance than that of the battery with PVDF. The PTH-bare S cathode with a mass loading of 5.97 mg/cm2 could deliver a capacity of 733.3 mAh/g at 0.2 C, and remained 585.5 mAh/g after 100 cycles. This in-situ polymerized binder is proved to be quite effective on restraining the volume expansion and suppressing polysulfide shuttle effect, then improving the electrochemical performance of Li-S battery.
2020, 31(2): 575-578
doi: 10.1016/j.cclet.2019.04.046
Abstract:
A series of Tm3+/Dy3+ co-doped Ba3LaNa(PO4)3F (BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction, and luminescence properties were investigated. Upon near violet excitation, BLNPF:Tm3+, Dy3+ phosphors exhibit Tm3+:1D2-3F4 and Dy3+:4F9/2-6HJ (J = 15/2, 13/2, 11/2) transitions with different luminescence intensity. The emitting color of the obtained products was found to shift from blue to white as a result of efficient energy transfer (ET) from Tm3+ to Dy3+ ions. According to photoluminescence emission intensity, the positive effect of activator on ETefficiency was calculated and the maximum ET efficiency was found around 72.6% with Dy3+ concentration was 0.04. By means of Dexter's theoretical model, furthermore, dipole-dipole interaction was confirmed as the mechanism of energy transfer from Tm3+ to Dy3+ ions. The results suggested that BLNPF:Tm3+, Dy3+ phosphor might be a promising single-phased white-light-emitting phosphor for UV white-light LED.
A series of Tm3+/Dy3+ co-doped Ba3LaNa(PO4)3F (BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction, and luminescence properties were investigated. Upon near violet excitation, BLNPF:Tm3+, Dy3+ phosphors exhibit Tm3+:1D2-3F4 and Dy3+:4F9/2-6HJ (J = 15/2, 13/2, 11/2) transitions with different luminescence intensity. The emitting color of the obtained products was found to shift from blue to white as a result of efficient energy transfer (ET) from Tm3+ to Dy3+ ions. According to photoluminescence emission intensity, the positive effect of activator on ETefficiency was calculated and the maximum ET efficiency was found around 72.6% with Dy3+ concentration was 0.04. By means of Dexter's theoretical model, furthermore, dipole-dipole interaction was confirmed as the mechanism of energy transfer from Tm3+ to Dy3+ ions. The results suggested that BLNPF:Tm3+, Dy3+ phosphor might be a promising single-phased white-light-emitting phosphor for UV white-light LED.
2020, 31(2): 579-582
doi: 10.1016/j.cclet.2019.05.035
Abstract:
Pore size and distribution in carbon-based materials are regarded to be a key factor to affect the electrochemical capacitive performances of the resultant electrodes. In this study, nitrogen and oxygen codoped porous carbons (NOPCs) are fabricated based on a simple Schiff-base reaction between m-phenylenediamine and terephthalaldehyde. The NOPCs have tunable morphologies, high surface areas, abundant heteroatom doping. More importantly, the carbons show a dominant micropores of 0.5-0.8 nm, comparable to the ionic sizes of LiTFSI (Li+ 0.069 nm; TFSI-0.79 nm) water-in-salt electrolyte with a high potential window of 2.2 V. Consequently, the fabricated symmetric supercapacitor gives a high energy output of 30.5 Wh/kg at 1 kW/kg, and high stability after successive 10, 000 cycles with ~96.8% retention. This study provides promising potential to develop high-energy supercapacitors.
Pore size and distribution in carbon-based materials are regarded to be a key factor to affect the electrochemical capacitive performances of the resultant electrodes. In this study, nitrogen and oxygen codoped porous carbons (NOPCs) are fabricated based on a simple Schiff-base reaction between m-phenylenediamine and terephthalaldehyde. The NOPCs have tunable morphologies, high surface areas, abundant heteroatom doping. More importantly, the carbons show a dominant micropores of 0.5-0.8 nm, comparable to the ionic sizes of LiTFSI (Li+ 0.069 nm; TFSI-0.79 nm) water-in-salt electrolyte with a high potential window of 2.2 V. Consequently, the fabricated symmetric supercapacitor gives a high energy output of 30.5 Wh/kg at 1 kW/kg, and high stability after successive 10, 000 cycles with ~96.8% retention. This study provides promising potential to develop high-energy supercapacitors.
2020, 31(2): 583-588
doi: 10.1016/j.cclet.2019.11.002
Abstract:
Biomass-derived carbon materials have obtained great attention due to their sustainability, easy availability, low cost and environmentally benign. In this work, bamboo leaves derived nitrogen doped hierarchically porous carbon have been efficiently synthesized via an annealing approach, followed by an etching process in HF solution. Electrochemical measurements demonstrate that the unique porous structure, together with the inherent high nitrogen content, endow the as-derived carbon with excellent lithium/sodium storage performance. The porous carbon annealed at 700 ℃ presents outstanding rate capability and remarkable long-term stability as anodes for both lithium-ion batteries and sodium-ion batteries. The optimized carbon delivers a high discharge capacity of 450 mAh/g after 500 cycles at the current density of 0.2 A/g for LIBs, and a discharge capacity of 180 mAh/g after 300 cycles at the current density of 0.1 A/g for SIBs
Biomass-derived carbon materials have obtained great attention due to their sustainability, easy availability, low cost and environmentally benign. In this work, bamboo leaves derived nitrogen doped hierarchically porous carbon have been efficiently synthesized via an annealing approach, followed by an etching process in HF solution. Electrochemical measurements demonstrate that the unique porous structure, together with the inherent high nitrogen content, endow the as-derived carbon with excellent lithium/sodium storage performance. The porous carbon annealed at 700 ℃ presents outstanding rate capability and remarkable long-term stability as anodes for both lithium-ion batteries and sodium-ion batteries. The optimized carbon delivers a high discharge capacity of 450 mAh/g after 500 cycles at the current density of 0.2 A/g for LIBs, and a discharge capacity of 180 mAh/g after 300 cycles at the current density of 0.1 A/g for SIBs
2020, 31(2): 361-364
doi: 10.1016/j.cclet.2019.07.040
Abstract:
Aggregation-induced emission (AIE) active photochromic molecules have attracted growing attention for their versatile applications. Here we designed and synthesized five newly unsymmetrical photochromic diarylethene (DAE) dyads (BTE1-5) by connecting tetraphenylethene (TPE) and aromatic substituent via bithienylethene (BTE) bridge. The chemical structures of those compounds were identified by 1H NMR, 13C NMR and HRMS.The absorption and emission of these dyads were investigated by UV-vis and fluorescence spectroscopy, respectively. The results showed that all those compounds exhibited typically AIE or aggregation-induced emission enhancement (AIEE) characteristic. Particularly, when an aggregation caused quenching (ACQ) fluorophore (triphenylamine) was grafted to the molecule, connecting with TPE via BTE-bridge, the ACQ phenomenon was dissipated and converted to an AIE luminophore, and those compounds exhibited photochromism upon irradiation with alternative UV and visible light. The solution or solid of those compounds showed distinctly fluorescence switching "ON" or "OFF" observation upon irradiation with alternative UV and visible light.It is interesting that BTE1 could be applied in recording and rewritable information storage, and the cyclization quantum yields could be affected by substituent significantly.
Aggregation-induced emission (AIE) active photochromic molecules have attracted growing attention for their versatile applications. Here we designed and synthesized five newly unsymmetrical photochromic diarylethene (DAE) dyads (BTE1-5) by connecting tetraphenylethene (TPE) and aromatic substituent via bithienylethene (BTE) bridge. The chemical structures of those compounds were identified by 1H NMR, 13C NMR and HRMS.The absorption and emission of these dyads were investigated by UV-vis and fluorescence spectroscopy, respectively. The results showed that all those compounds exhibited typically AIE or aggregation-induced emission enhancement (AIEE) characteristic. Particularly, when an aggregation caused quenching (ACQ) fluorophore (triphenylamine) was grafted to the molecule, connecting with TPE via BTE-bridge, the ACQ phenomenon was dissipated and converted to an AIE luminophore, and those compounds exhibited photochromism upon irradiation with alternative UV and visible light. The solution or solid of those compounds showed distinctly fluorescence switching "ON" or "OFF" observation upon irradiation with alternative UV and visible light.It is interesting that BTE1 could be applied in recording and rewritable information storage, and the cyclization quantum yields could be affected by substituent significantly.
2020, 31(2): 365-368
doi: 10.1016/j.cclet.2019.07.044
Abstract:
Polylactic acid (PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application. However, there is still a lack of a green and facile way to prepare PLA oil-water separation materials. In this work, a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported. The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight. In addition, it could also be applicated as a filter with excellent efficiency (50.9 m3 m-2 h-1).
Polylactic acid (PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application. However, there is still a lack of a green and facile way to prepare PLA oil-water separation materials. In this work, a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported. The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight. In addition, it could also be applicated as a filter with excellent efficiency (50.9 m3 m-2 h-1).
2020, 31(2): 369-372
doi: 10.1016/j.cclet.2019.07.048
Abstract:
Host-guest supramolecular gels were developed via the self-assembly of inclusion complexes (ICs) of β-cyclodextrins/phenylboronic acid gelator (PBA). Salts and current were involved in the self-assembly to stabilize the host-guest gels. The stability of the gels was greatly improved after salts were added. The stable time of gels was extended from 2.5 h to 120 h with the addition of NH4NO3 at the concentration of 2.5×10-2 g/mL. The morphology of the gel was affected by the concentrations of NH4NO3. SEM images revealed that the gels were three-dimensional nanofibrous networks, the sizes of fibers decreased with decreasing NH4NO3 concentrations, which affected the stability of gels, further proved by the rheological properties of gels. More stable gels were obtained with current stimulation, the stable time of the gel was increased from 2.5 h to 55 h with current by adding NaBF4. The current also exhibited significant influence on the aggregation as the voltage varied (0-500 mV) with a constant concentration of salts. The result showed the self-assembly process of host-guest gel could be well controlled via the addition of salts and current to desired morphology and stability.
Host-guest supramolecular gels were developed via the self-assembly of inclusion complexes (ICs) of β-cyclodextrins/phenylboronic acid gelator (PBA). Salts and current were involved in the self-assembly to stabilize the host-guest gels. The stability of the gels was greatly improved after salts were added. The stable time of gels was extended from 2.5 h to 120 h with the addition of NH4NO3 at the concentration of 2.5×10-2 g/mL. The morphology of the gel was affected by the concentrations of NH4NO3. SEM images revealed that the gels were three-dimensional nanofibrous networks, the sizes of fibers decreased with decreasing NH4NO3 concentrations, which affected the stability of gels, further proved by the rheological properties of gels. More stable gels were obtained with current stimulation, the stable time of the gel was increased from 2.5 h to 55 h with current by adding NaBF4. The current also exhibited significant influence on the aggregation as the voltage varied (0-500 mV) with a constant concentration of salts. The result showed the self-assembly process of host-guest gel could be well controlled via the addition of salts and current to desired morphology and stability.
2020, 31(2): 373-376
doi: 10.1016/j.cclet.2019.07.049
Abstract:
A new silver mediated aminophosphinoylation of propargyl alcohols with aromatic amines and Hphosphine oxides for the construction of α-aminophosphine oxides has been developed. The C-N and C-P bond could be efficiently formed in one pot operation via sequential C-C and C-O bond cleavage of propargylic alcohols. This present methodology, which not only provides a simple and alternative strategy for the synthesis of α-aminophosphine oxides, but also opens a new window for the cleavage reactions of propargyl alcohols via dealkynalation coupling.
A new silver mediated aminophosphinoylation of propargyl alcohols with aromatic amines and Hphosphine oxides for the construction of α-aminophosphine oxides has been developed. The C-N and C-P bond could be efficiently formed in one pot operation via sequential C-C and C-O bond cleavage of propargylic alcohols. This present methodology, which not only provides a simple and alternative strategy for the synthesis of α-aminophosphine oxides, but also opens a new window for the cleavage reactions of propargyl alcohols via dealkynalation coupling.
2020, 31(2): 377-380
doi: 10.1016/j.cclet.2019.07.052
Abstract:
An organocatalytic asymmetric [3+2] cycloaddition of trifluoromethyl-containing azomethine ylides with cyclic 2, 4-dienones was developed. The process enables efficient incorporation of CF3 groups into functionalized spiro[pyrrolidin-3, 2'-oxindoles] in high yields with good to excellent enantio-and diastereoselectivities.
An organocatalytic asymmetric [3+2] cycloaddition of trifluoromethyl-containing azomethine ylides with cyclic 2, 4-dienones was developed. The process enables efficient incorporation of CF3 groups into functionalized spiro[pyrrolidin-3, 2'-oxindoles] in high yields with good to excellent enantio-and diastereoselectivities.
2020, 31(2): 381-385
doi: 10.1016/j.cclet.2019.06.015
Abstract:
A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established, which constructed enantiomerically pure bispiro[benzofuran-oxindole/benzofuran-chromanone]s bearing five consecutive stereocenters including two spiro quaternary carton centers in good yields (up to 93%) with high diastereoselectivities (up to >20:1 dr) and good enantioselectivities (up to >99% ee). Moreover, this is the first example of bifunctional chromone-benzofuranone synthon directed organocatalytic tandem reaction, and also the first example of the bispiro[benzofuran-oxindole] and bispirobenzofuranone, potentially useful in medicinal chemistry.
A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established, which constructed enantiomerically pure bispiro[benzofuran-oxindole/benzofuran-chromanone]s bearing five consecutive stereocenters including two spiro quaternary carton centers in good yields (up to 93%) with high diastereoselectivities (up to >20:1 dr) and good enantioselectivities (up to >99% ee). Moreover, this is the first example of bifunctional chromone-benzofuranone synthon directed organocatalytic tandem reaction, and also the first example of the bispiro[benzofuran-oxindole] and bispirobenzofuranone, potentially useful in medicinal chemistry.
2020, 31(2): 386-390
doi: 10.1016/j.cclet.2019.06.050
Abstract:
A heteropore covalent organic framework (COF) integrating tetraphenylethene skeleton and catechol segment is designed and synthesized. It exhibits extremely high stability in water under different pH conditions, which makes it an excellent material for adsorptive removal of Cd(Ⅱ) from aqueous solutions with very fast adsorption kinetics, high uptake capacity, and good recyclability.
A heteropore covalent organic framework (COF) integrating tetraphenylethene skeleton and catechol segment is designed and synthesized. It exhibits extremely high stability in water under different pH conditions, which makes it an excellent material for adsorptive removal of Cd(Ⅱ) from aqueous solutions with very fast adsorption kinetics, high uptake capacity, and good recyclability.
2020, 31(2): 391-395
doi: 10.1016/j.cclet.2019.07.030
Abstract:
An efficient water-based bismuth-mediated addition reaction of carbonyl compound with cyclic allylic halide was developed. The reactions proceeded smoothly in aqueous DMF in the presence of ammonium iodide to afford the corresponding syn-homoallylic alcohols in moderate to good yields with excellent diastereoselectivities (>99:1 syn:anti). Reversal of product diastereoselectivity was observed when heteroaryl aldehyde possessing an adjacent chelating nitrogen atom was employed as substrate.
An efficient water-based bismuth-mediated addition reaction of carbonyl compound with cyclic allylic halide was developed. The reactions proceeded smoothly in aqueous DMF in the presence of ammonium iodide to afford the corresponding syn-homoallylic alcohols in moderate to good yields with excellent diastereoselectivities (>99:1 syn:anti). Reversal of product diastereoselectivity was observed when heteroaryl aldehyde possessing an adjacent chelating nitrogen atom was employed as substrate.
2020, 31(2): 396-400
doi: 10.1016/j.cclet.2019.09.025
Abstract:
A selective ring-opening [3+2] cyclization reaction of benzo[d]isoxazoles with 2-bromo-propanamides has been developed. The azaoxyallyl cation intermediates are employed as C~O 3-atom synthon to build oxa-heterocycles via the selectivity of suitable cyclization partners. This transformation provides rapid access to highly functionalized 2-hydroxyaryl-oxazolines under mild conditions and excellent regioselectivity.
A selective ring-opening [3+2] cyclization reaction of benzo[d]isoxazoles with 2-bromo-propanamides has been developed. The azaoxyallyl cation intermediates are employed as C~O 3-atom synthon to build oxa-heterocycles via the selectivity of suitable cyclization partners. This transformation provides rapid access to highly functionalized 2-hydroxyaryl-oxazolines under mild conditions and excellent regioselectivity.
2020, 31(2): 401-403
doi: 10.1016/j.cclet.2019.06.048
Abstract:
A seven-step total synthesis of α-cyclopiazonic acid is reported from a commercially available 4-bromoindole. Salient feature of the work is the rapid formation of tetracyclic skeleton via a bioinspired [3+2] annulation to form the C/D rings.
A seven-step total synthesis of α-cyclopiazonic acid is reported from a commercially available 4-bromoindole. Salient feature of the work is the rapid formation of tetracyclic skeleton via a bioinspired [3+2] annulation to form the C/D rings.
2020, 31(2): 404-408
doi: 10.1016/j.cclet.2019.06.019
Abstract:
In this study, we designed and synthesized a series of phthalazinone acridine derivatives as dual PARP and Topo inhibitors. MTT assays indicated that most of the compounds significantly inhibited multiple cancer cells proliferation. In addition, all the compounds displayed Topo Ⅱ inhibition activity at 10 mol/L, and also possessed good PARP-1 inhibitory activities. Subsequent mechanistic studies showed that compound 9a induced remarkable apoptosis and caused prominent S cell cycle arrest in HCT116 cells. Our study suggested that 9a inhibiting Topo and PARP concurrently can be a potential lead compound for cancer therapy.
In this study, we designed and synthesized a series of phthalazinone acridine derivatives as dual PARP and Topo inhibitors. MTT assays indicated that most of the compounds significantly inhibited multiple cancer cells proliferation. In addition, all the compounds displayed Topo Ⅱ inhibition activity at 10 mol/L, and also possessed good PARP-1 inhibitory activities. Subsequent mechanistic studies showed that compound 9a induced remarkable apoptosis and caused prominent S cell cycle arrest in HCT116 cells. Our study suggested that 9a inhibiting Topo and PARP concurrently can be a potential lead compound for cancer therapy.
2020, 31(2): 409-412
doi: 10.1016/j.cclet.2019.07.038
Abstract:
Seven 2, 6-disubstituted N-(2-phenoxy)ethyl imidazo[1, 2-a]pyridine-3-carboxamide series containing various amine moieties were designed and synthesized as new anti-TB agents. Many of them show excellent in vitro activity against both drug-sensitive MTB strain H37Rv and two MDR-MTB clinical isolates (MIC: < 0.002-0.030 μg/mL). Compounds 2f, 5e and 5g display acceptable safety and pharmacokinetic profiles, opening a new direction for further development.
Seven 2, 6-disubstituted N-(2-phenoxy)ethyl imidazo[1, 2-a]pyridine-3-carboxamide series containing various amine moieties were designed and synthesized as new anti-TB agents. Many of them show excellent in vitro activity against both drug-sensitive MTB strain H37Rv and two MDR-MTB clinical isolates (MIC: < 0.002-0.030 μg/mL). Compounds 2f, 5e and 5g display acceptable safety and pharmacokinetic profiles, opening a new direction for further development.
2020, 31(2): 413-417
doi: 10.1016/j.cclet.2019.07.063
Abstract:
Polymyxin B (PB), as the last-line of defense against multidrug-resistant Gram-negative bacteria, has caused resistance to P. aeruginosa recently. Fortunately, synergistic treatment could preserve the last class of antibiotics and reduce the emergency of drug resistance. Here, we performed a screen of 970 approved drugs synergized with PB against the P. aeruginosa DK2, which is severely resistant to PB, MIC = 512 μg/mL. Encouragingly, we found fluoroquinolones could synergy with PB and achieved an obvious reduction in MIC of PB below the clinical susceptible breakpoint (2 μg/mL). Especially, gemifloxacin achieved the highest synergistic effect with PB, leading to a 4096-fold MIC reduction (reduced from 512 μg/mL to 0.125 μg/mL). Furthermore, synergistic effect was also observed in the combination of gemifloxacin and colistin. Finally, outer membrane permeabilization assay showed that gemifloxacin could increase the permeability of bacterial cell membranes for P. aeruginosa which partly explained the synergy mechanism. These results indicate that fluoroquinolones represent attractive synergists to address the emerging threat of polymyxin-resistant infections.
Polymyxin B (PB), as the last-line of defense against multidrug-resistant Gram-negative bacteria, has caused resistance to P. aeruginosa recently. Fortunately, synergistic treatment could preserve the last class of antibiotics and reduce the emergency of drug resistance. Here, we performed a screen of 970 approved drugs synergized with PB against the P. aeruginosa DK2, which is severely resistant to PB, MIC = 512 μg/mL. Encouragingly, we found fluoroquinolones could synergy with PB and achieved an obvious reduction in MIC of PB below the clinical susceptible breakpoint (2 μg/mL). Especially, gemifloxacin achieved the highest synergistic effect with PB, leading to a 4096-fold MIC reduction (reduced from 512 μg/mL to 0.125 μg/mL). Furthermore, synergistic effect was also observed in the combination of gemifloxacin and colistin. Finally, outer membrane permeabilization assay showed that gemifloxacin could increase the permeability of bacterial cell membranes for P. aeruginosa which partly explained the synergy mechanism. These results indicate that fluoroquinolones represent attractive synergists to address the emerging threat of polymyxin-resistant infections.
2020, 31(2): 418-422
doi: 10.1016/j.cclet.2019.08.029
Abstract:
Targeting bromodomain-containing protein 4 (BRD4) has been proved to be an effective strategy for cancer therapy. To date, numerous BRD4 inhibitors and degraders have been identified, some of which have advanced into clinical trials. In this work, a focused library of new [1, 2, 4]triazolo[1, 5-a]pyrimidine derivatives were discovered to be able to inhibit BRD4. WS-722 inactivated BRD4 (BD1/BD2), BRD2 (BD1/BD2) and BRD3 (BD1/BD2) broadly with the IC50 values less than 5 μmol/L. Besides, WS-722 inhibited growth of THP-1 cells with an IC50 value of 3.86 μmol/L. Like (+)-JQ1, WS-722 inhibited BRD4 in a reversible manner and enhanced protein stability. Docking studies showed that WS-722 occupied the central acetyl-lysine (Kac) binding cavity and formed a hydrogen bond with Asn140. In THP-1 cells, WS-722 showed target engagement to BRD4. Cellular effects of WS-722 on THP-1 cells were also examined, showing that WS-722 could block c-MYC expression, induce G0/G1 phase arrest and p21 up-regulation, and promote differentiation of THP-1 cells. BRD4 inhibition by WS-722 resulted in cell apoptosis and upregulated expression of cleaved caspased-3/7 and PARP in THP-1 cell lines. The [1, 2, 4]triazolo[1, 5-a] pyrimidine is a new template for the development of new BRD4 inhibitors.
Targeting bromodomain-containing protein 4 (BRD4) has been proved to be an effective strategy for cancer therapy. To date, numerous BRD4 inhibitors and degraders have been identified, some of which have advanced into clinical trials. In this work, a focused library of new [1, 2, 4]triazolo[1, 5-a]pyrimidine derivatives were discovered to be able to inhibit BRD4. WS-722 inactivated BRD4 (BD1/BD2), BRD2 (BD1/BD2) and BRD3 (BD1/BD2) broadly with the IC50 values less than 5 μmol/L. Besides, WS-722 inhibited growth of THP-1 cells with an IC50 value of 3.86 μmol/L. Like (+)-JQ1, WS-722 inhibited BRD4 in a reversible manner and enhanced protein stability. Docking studies showed that WS-722 occupied the central acetyl-lysine (Kac) binding cavity and formed a hydrogen bond with Asn140. In THP-1 cells, WS-722 showed target engagement to BRD4. Cellular effects of WS-722 on THP-1 cells were also examined, showing that WS-722 could block c-MYC expression, induce G0/G1 phase arrest and p21 up-regulation, and promote differentiation of THP-1 cells. BRD4 inhibition by WS-722 resulted in cell apoptosis and upregulated expression of cleaved caspased-3/7 and PARP in THP-1 cell lines. The [1, 2, 4]triazolo[1, 5-a] pyrimidine is a new template for the development of new BRD4 inhibitors.
2020, 31(2): 423-426
doi: 10.1016/j.cclet.2019.06.006
Abstract:
Four new seco-dibenzocyclooctadiene lignans, kadlongilignans A-D (1-4), consisting of a rare 6, 7-seco-(1), two 15, 16-seco-(2 and 3) and a 9, 10-seco-dibenzocyclooctadiene (4) lignans, were isolated from the roots of Kadsura longipedunculata. Their structures were elucidated by spectroscopic analysis, including extensive NMR, MS and ECD (electronic circular dichroism) spectra. Compounds 3 and 4 exhibited potent inhibitory activities against NO (nitric oxide) production of LPS (lipopolysaccharide)-induced murine macrophages with the inhibition rates of 36.3% and 26.9%, respectively.
Four new seco-dibenzocyclooctadiene lignans, kadlongilignans A-D (1-4), consisting of a rare 6, 7-seco-(1), two 15, 16-seco-(2 and 3) and a 9, 10-seco-dibenzocyclooctadiene (4) lignans, were isolated from the roots of Kadsura longipedunculata. Their structures were elucidated by spectroscopic analysis, including extensive NMR, MS and ECD (electronic circular dichroism) spectra. Compounds 3 and 4 exhibited potent inhibitory activities against NO (nitric oxide) production of LPS (lipopolysaccharide)-induced murine macrophages with the inhibition rates of 36.3% and 26.9%, respectively.
2020, 31(2): 427-430
doi: 10.1016/j.cclet.2019.09.020
Abstract:
Callicarpa bodinieri is a Chinese traditional medicine herbwith anti-inflammatory activity in clinic. Herein, we report two new 9, 10-seco and etherified abietane diterpenoids bodinieric acids J and K(1 and 2)and one known compound (3) isolated from the leaves and twigs of this plant. Their chemical structures were elucidated by detailed spectrometry data analysis and DP4+ NMR calculation methods. Hypothetical biosynthetic pathways of 1-3 were preliminarily speculated. Compound 3 inhibited inflammasome activation and exhibited blockage of NLRP3 inflammasome activation at non-cytotoxic concentrations in vitro.
Callicarpa bodinieri is a Chinese traditional medicine herbwith anti-inflammatory activity in clinic. Herein, we report two new 9, 10-seco and etherified abietane diterpenoids bodinieric acids J and K(1 and 2)and one known compound (3) isolated from the leaves and twigs of this plant. Their chemical structures were elucidated by detailed spectrometry data analysis and DP4+ NMR calculation methods. Hypothetical biosynthetic pathways of 1-3 were preliminarily speculated. Compound 3 inhibited inflammasome activation and exhibited blockage of NLRP3 inflammasome activation at non-cytotoxic concentrations in vitro.
2020, 31(2): 431-433
doi: 10.1016/j.cclet.2019.07.068
Abstract:
A novel meroterpenoid, euphoractone (1), was isolated from the extracts of the roots of Euphorbia fischeriana Steud. Its structure was determined by spectroscopic methods and X-ray crystallography. 1 possesses an unusual ent-abietane-phloroglucinol skeleton. The plausible biosynthetic pathway for 1 was proposed.1 showed inhibitory activities against human lung cancer H23 and H460 cells with the IC50 values of 21.07±3.54 and 20.91±4.07 μmol/L.
A novel meroterpenoid, euphoractone (1), was isolated from the extracts of the roots of Euphorbia fischeriana Steud. Its structure was determined by spectroscopic methods and X-ray crystallography. 1 possesses an unusual ent-abietane-phloroglucinol skeleton. The plausible biosynthetic pathway for 1 was proposed.1 showed inhibitory activities against human lung cancer H23 and H460 cells with the IC50 values of 21.07±3.54 and 20.91±4.07 μmol/L.
2020, 31(2): 434-438
doi: 10.1016/j.cclet.2019.06.037
Abstract:
A series of structurally novel 1, 3, 4-oxadiazole thioether derivatives (6a-6z) containing a 6-fluoroquinazolinylpiperidinyl moiety were designed and synthesized using pharmacophore hybrid approach, and their structures were fully characterized by 1H NMR, 13C NMR and HRMS spectra. Among them, the structure of compound 6d was further corroborated via single-crystal X-ray diffraction analysis. In vitro antibacterial bioassays showed that compounds 6a, 6g, 6u and 6v possessed EC50 values of 30.4, 30.6, 27.5 and 26.0 μg/mL against phytopathogenic bacterium Xanthomonas oryzae pv. oryzae, respectively, which were significantly superior to that of commercially-available bactericide Bismerthiazol (85.1 μg/mL). Moreover, in vitro antifungal bioassays indicated that seven compounds demonstrated broad-spectrum fungicidal acitivties against six types of phytopathogenic fungi at 50 μg/mL. The present work showed the potential of 1, 3, 4-oxadiazole thioether derivatives carrying a 6-fluoroquinazolinylpiperidinyl moiety as effective antimicrobial agents for crop protection, deserving further investigations in the future.
A series of structurally novel 1, 3, 4-oxadiazole thioether derivatives (6a-6z) containing a 6-fluoroquinazolinylpiperidinyl moiety were designed and synthesized using pharmacophore hybrid approach, and their structures were fully characterized by 1H NMR, 13C NMR and HRMS spectra. Among them, the structure of compound 6d was further corroborated via single-crystal X-ray diffraction analysis. In vitro antibacterial bioassays showed that compounds 6a, 6g, 6u and 6v possessed EC50 values of 30.4, 30.6, 27.5 and 26.0 μg/mL against phytopathogenic bacterium Xanthomonas oryzae pv. oryzae, respectively, which were significantly superior to that of commercially-available bactericide Bismerthiazol (85.1 μg/mL). Moreover, in vitro antifungal bioassays indicated that seven compounds demonstrated broad-spectrum fungicidal acitivties against six types of phytopathogenic fungi at 50 μg/mL. The present work showed the potential of 1, 3, 4-oxadiazole thioether derivatives carrying a 6-fluoroquinazolinylpiperidinyl moiety as effective antimicrobial agents for crop protection, deserving further investigations in the future.
2020, 31(2): 439-442
doi: 10.1016/j.cclet.2019.08.051
Abstract:
Here, a new designed core/satellite gold nanoprobe was developed for detecting trace mount of benzoyl peroxide (BPO) based on its deboronation. This gold nanoassembly (the BE-AuNPs12/65) was constructed via borate ester formation between large 4-mercaptophenylboronic acid (MPBA) modified AuNPs (the MPBA-AuNPs65, as cores)and smalldopamine modifiedAuNPs (theDPA-AuNPs12, assatellites).Particularly, upon addition of BPO, it would trigger the deboronation for the BE-AuNPs12/65 probes accompanying with distinct color changes from blue, purple to wine red, which implied the disassembly of the core/satellite nanostructure after the breakage of carbon to boron chemical bond. By measuring the absorbance ratio at 665 nm and 545 nm, quantification of BPO was achieved in the range of 10.0-100.0 nmol/L, which could also be easilyobserved bynaked eyes. The nanoprobeutilized a boronate deprotection mechanism and the LSPR properties of AuNPs to provide high selectivity for detecting BPO over similar ROS/RNS with the limit of detection as low as 7.2 nmol/L. The practical applicability of this assay was verified through successful determining BPO in flour samples, which demonstrated its great potentials in food safety field.
Here, a new designed core/satellite gold nanoprobe was developed for detecting trace mount of benzoyl peroxide (BPO) based on its deboronation. This gold nanoassembly (the BE-AuNPs12/65) was constructed via borate ester formation between large 4-mercaptophenylboronic acid (MPBA) modified AuNPs (the MPBA-AuNPs65, as cores)and smalldopamine modifiedAuNPs (theDPA-AuNPs12, assatellites).Particularly, upon addition of BPO, it would trigger the deboronation for the BE-AuNPs12/65 probes accompanying with distinct color changes from blue, purple to wine red, which implied the disassembly of the core/satellite nanostructure after the breakage of carbon to boron chemical bond. By measuring the absorbance ratio at 665 nm and 545 nm, quantification of BPO was achieved in the range of 10.0-100.0 nmol/L, which could also be easilyobserved bynaked eyes. The nanoprobeutilized a boronate deprotection mechanism and the LSPR properties of AuNPs to provide high selectivity for detecting BPO over similar ROS/RNS with the limit of detection as low as 7.2 nmol/L. The practical applicability of this assay was verified through successful determining BPO in flour samples, which demonstrated its great potentials in food safety field.
2020, 31(2): 443-446
doi: 10.1016/j.cclet.2019.07.047
Abstract:
A ratiometric fluorescent hybrid nanoprobe CDs-1 for arginine (Arg), exhibiting high sensitivity (the limit of detection, LOD, being 6.5×10-8 mol/L) and excellent selectivity and anti-interference ability, was fabricated through fluorescence resonance energy transfer (FRET) and the electrostatic attraction between positively-charged hemicyanine molecules and negatively-charged carbon dots (CDs). Arg can be quantitatively detected in the concentration range from 6.0×10-5 mol/L to 2.7×10-4 mol/L. Further, due to its ability to target mitochondrion and low cytotoxicity, intracellular Arg was successfully tracked through ratiometric fluorescence imaging.
A ratiometric fluorescent hybrid nanoprobe CDs-1 for arginine (Arg), exhibiting high sensitivity (the limit of detection, LOD, being 6.5×10-8 mol/L) and excellent selectivity and anti-interference ability, was fabricated through fluorescence resonance energy transfer (FRET) and the electrostatic attraction between positively-charged hemicyanine molecules and negatively-charged carbon dots (CDs). Arg can be quantitatively detected in the concentration range from 6.0×10-5 mol/L to 2.7×10-4 mol/L. Further, due to its ability to target mitochondrion and low cytotoxicity, intracellular Arg was successfully tracked through ratiometric fluorescence imaging.
2020, 31(2): 447-450
doi: 10.1016/j.cclet.2019.07.046
Abstract:
A novel donor-acceptor (D-A) type of two-photon (TP) fluorescent probe, i.e. Lyso-OSC, based on the lysosome-targeting morpholine group was developed. The polarity sensing coumarin group was functionalized as the acceptor and the 1-vinyl-4-methoxybenzene group was engineered as the donor. The fluorescence intensity and emission maximum wavelength of Lyso-OSC are highly sensitive to the polarity changes of solvent. The two-photon absorption cross-section and tissue penetration depth are up to 254 GM and 150 μm, respectively. The strong fluorescence, high sensitivity to polarity, low cytotoxicity, and accurate lysosome-targeting ability entail Lyso-OSC the excellent performance in detecting the polarity changes of cellular environment. To this end, a bright, real-time imaging autophagy of living cells has been achieved.
A novel donor-acceptor (D-A) type of two-photon (TP) fluorescent probe, i.e. Lyso-OSC, based on the lysosome-targeting morpholine group was developed. The polarity sensing coumarin group was functionalized as the acceptor and the 1-vinyl-4-methoxybenzene group was engineered as the donor. The fluorescence intensity and emission maximum wavelength of Lyso-OSC are highly sensitive to the polarity changes of solvent. The two-photon absorption cross-section and tissue penetration depth are up to 254 GM and 150 μm, respectively. The strong fluorescence, high sensitivity to polarity, low cytotoxicity, and accurate lysosome-targeting ability entail Lyso-OSC the excellent performance in detecting the polarity changes of cellular environment. To this end, a bright, real-time imaging autophagy of living cells has been achieved.
2020, 31(2): 451-454
doi: 10.1016/j.cclet.2019.07.036
Abstract:
In this work, a multi-functional analysis platform by coupling a microfluidic chip to a mass spectrometry (MS) detector was described. We constructed a three-dimensional tumor-endothelial co-culture model for simulating drug resistance during tumor treatment. On this specially designed integrated platform, the first step was to prepare heterogeneous cell-encapsulated alginate microcapsules for threedimensional co-culture, and the second step was to achieve on-line perfusion culture and continuous drug stimulation on chip. It facilitates cell proliferation analysis and the collection of metabolism medium. After micro solid phase extraction column (SPE) pretreatment, subsequent mass spectrometry could detect drug metabolism. The high activity of two kinds of cells (A549 and HUVEC) shows the biocompatibility of the platform. Paclitaxel was used as a model drug, the distinctions of drug absorption between the mono-culture group and co-culture group were clearly observed by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF MS). Therefore, the integrated platform has shown promise as a high throughput, low cost for cell metabolism research and drug screening processes.
In this work, a multi-functional analysis platform by coupling a microfluidic chip to a mass spectrometry (MS) detector was described. We constructed a three-dimensional tumor-endothelial co-culture model for simulating drug resistance during tumor treatment. On this specially designed integrated platform, the first step was to prepare heterogeneous cell-encapsulated alginate microcapsules for threedimensional co-culture, and the second step was to achieve on-line perfusion culture and continuous drug stimulation on chip. It facilitates cell proliferation analysis and the collection of metabolism medium. After micro solid phase extraction column (SPE) pretreatment, subsequent mass spectrometry could detect drug metabolism. The high activity of two kinds of cells (A549 and HUVEC) shows the biocompatibility of the platform. Paclitaxel was used as a model drug, the distinctions of drug absorption between the mono-culture group and co-culture group were clearly observed by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF MS). Therefore, the integrated platform has shown promise as a high throughput, low cost for cell metabolism research and drug screening processes.
2020, 31(2): 455-458
doi: 10.1016/j.cclet.2019.07.067
Abstract:
Ribonucleotides are usually functioned as biomarkers to diagnose diseases and monitor the life activities in living organisms, and their discrimination is of great significance but challenging. Taking advantage of the unique characteristics of gold nanorods (AuNRs), herein, a colorimetric sensor array for discrimination of twelve ribonucleotides was developed based on the chemical etching of AuNRs with controllable aspect ratios. During the etching process, AuNRs were preferentially shortened and eventually turned into Au(Ⅲ) state by Fenton's reaction. The morphological change of AuNRs led to the significant color change and blue shift in the corresponding extinction spectrum. However, when Fe2+ bound with ribonucleotides, the Fenton's reaction was prevented and the ability to etch AuNRs was weakened or disappeared. Due to the different structures of nucleotides, the binding ability of them with Fe2+ was distinct, resulting in the discrepancy in the chemical etching of AuNRs, which could be developed for distinguishing ribonucleotides. Moreover, the proposed sensor array was successfully explored to distinguish ribonucleotides in complex human urine samples.
Ribonucleotides are usually functioned as biomarkers to diagnose diseases and monitor the life activities in living organisms, and their discrimination is of great significance but challenging. Taking advantage of the unique characteristics of gold nanorods (AuNRs), herein, a colorimetric sensor array for discrimination of twelve ribonucleotides was developed based on the chemical etching of AuNRs with controllable aspect ratios. During the etching process, AuNRs were preferentially shortened and eventually turned into Au(Ⅲ) state by Fenton's reaction. The morphological change of AuNRs led to the significant color change and blue shift in the corresponding extinction spectrum. However, when Fe2+ bound with ribonucleotides, the Fenton's reaction was prevented and the ability to etch AuNRs was weakened or disappeared. Due to the different structures of nucleotides, the binding ability of them with Fe2+ was distinct, resulting in the discrepancy in the chemical etching of AuNRs, which could be developed for distinguishing ribonucleotides. Moreover, the proposed sensor array was successfully explored to distinguish ribonucleotides in complex human urine samples.
2020, 31(2): 459-462
doi: 10.1016/j.cclet.2019.08.050
Abstract:
This article describes a fast and simple electrochemical assay for detecting cell concentration. After cell death, the membrane of cells will be broken, and DNA molecules contained in the cells will be released, but this does not happen in living cells. Sodium molybdate can react with the phosphate backbone of the released DNA molecules to form phosphomolybdate precipitation and produces a corresponding redox current. The higher the concentration of DNA, the stronger the intensity of the current generated. Sodium molybdate solution and centrifuged cell supernatant were added onto the glassy carbon electrode to determine the cell concentration by measuring the current intensity. The cell viability, which means the ratio of living cells to the total cells, can also be determined by this method. This assay has the advantages of high sensitivity, low detection limit, and wide detection range. In addition, this method was successfully applied to the detection of cell concentration in human serum, which has potential clinical applications.
This article describes a fast and simple electrochemical assay for detecting cell concentration. After cell death, the membrane of cells will be broken, and DNA molecules contained in the cells will be released, but this does not happen in living cells. Sodium molybdate can react with the phosphate backbone of the released DNA molecules to form phosphomolybdate precipitation and produces a corresponding redox current. The higher the concentration of DNA, the stronger the intensity of the current generated. Sodium molybdate solution and centrifuged cell supernatant were added onto the glassy carbon electrode to determine the cell concentration by measuring the current intensity. The cell viability, which means the ratio of living cells to the total cells, can also be determined by this method. This assay has the advantages of high sensitivity, low detection limit, and wide detection range. In addition, this method was successfully applied to the detection of cell concentration in human serum, which has potential clinical applications.
2020, 31(2): 468-472
doi: 10.1016/j.cclet.2019.08.012
Abstract:
The concentration of free zinc within insulin-storing vesicles is important for vesicle maturity and therefore requires accurate measurement. However, common small-molecule intensity-based probes and most available genetically encoded Förster resonance energy transfer (FRET)-based sensors for zinc are unsuitable for estimating the free zinc concentration in insulin-storing vesicles. Therefore, we have developed a novel FRET-based zinc sensor based on the RING motif of TRIM72, referred to as ZnT72R, which has an approximate Kd that varies from 6.07±0.28 μmol/L to 7.84±0.42 μmol/L in vitro and a cytosol-calibrated Kd of approximately 55.56±4.59 μmol/L in HEK293 T cells. To pinpoint the free zinc concentration of insulin-storing vesicles, we initially targeted ZnT72R to beta-cell vesicles by fusing them to NPY (neuropeptide Y). Following NPY-ZnT72R labeling, the FRET intensity ratios of vesicles were quantified. We found that the free zinc concentration in insulin-storing vesicles of diabetic db/db mice (28.30±1.33 μmol/L) was significantly lower than that of control mice (41.46±3.53 μmol/L).
The concentration of free zinc within insulin-storing vesicles is important for vesicle maturity and therefore requires accurate measurement. However, common small-molecule intensity-based probes and most available genetically encoded Förster resonance energy transfer (FRET)-based sensors for zinc are unsuitable for estimating the free zinc concentration in insulin-storing vesicles. Therefore, we have developed a novel FRET-based zinc sensor based on the RING motif of TRIM72, referred to as ZnT72R, which has an approximate Kd that varies from 6.07±0.28 μmol/L to 7.84±0.42 μmol/L in vitro and a cytosol-calibrated Kd of approximately 55.56±4.59 μmol/L in HEK293 T cells. To pinpoint the free zinc concentration of insulin-storing vesicles, we initially targeted ZnT72R to beta-cell vesicles by fusing them to NPY (neuropeptide Y). Following NPY-ZnT72R labeling, the FRET intensity ratios of vesicles were quantified. We found that the free zinc concentration in insulin-storing vesicles of diabetic db/db mice (28.30±1.33 μmol/L) was significantly lower than that of control mice (41.46±3.53 μmol/L).
2020, 31(2): 473-475
doi: 10.1016/j.cclet.2019.07.057
Abstract:
The observation of single-particle surface-enhanced Raman scattering (SERS) has generated considerable interest both in the nanomaterials filed and in the single-particle spectroscopy community. It is a challenge to realize rapid, facile, and high throughput SERS at single nanoparticle level. Here, without the complex experimental device and difficult experimental operations, a general single-particle SERS technique has been achieved by using dark-field-assisted surface-enhanced Raman spectroscopy (DFSERS). This advanced method provides in-situ characterization of the chemical reaction performance at single gold nanorod.
The observation of single-particle surface-enhanced Raman scattering (SERS) has generated considerable interest both in the nanomaterials filed and in the single-particle spectroscopy community. It is a challenge to realize rapid, facile, and high throughput SERS at single nanoparticle level. Here, without the complex experimental device and difficult experimental operations, a general single-particle SERS technique has been achieved by using dark-field-assisted surface-enhanced Raman spectroscopy (DFSERS). This advanced method provides in-situ characterization of the chemical reaction performance at single gold nanorod.
2020, 31(2): 476-478
doi: 10.1016/j.cclet.2019.07.066
Abstract:
Lung cancer is the most malignant tumor disease with the highest diagnosis and mortality rate in China. The development of therapeutic drugs is the current research focus. Dai-Bai-Jie is a traditional medicine of the Dai nationality, which is commonly used in the treatment of decreasing swelling, alleviating pain and detoxification. Most of the current researches focused on the component analysis of Dai-Bai-Jie, but few researches studied on its antitumor and pharmacological effect. In this study, we incubated A549 cells with different concentrations of Dai-Bai-Jie. The cell proliferation experiment showed that the DaiBai-Jie solution inhibited the proliferation of A549 cells and caused cell apoptosis. In this work, we confirmed that Dai-Bai-Jie had an inhibitory effect on the proliferation and migration of non-small cell lung cancer A549, which may be used as a novel candidate of anti-tumor therapy for lung cancer patients.
Lung cancer is the most malignant tumor disease with the highest diagnosis and mortality rate in China. The development of therapeutic drugs is the current research focus. Dai-Bai-Jie is a traditional medicine of the Dai nationality, which is commonly used in the treatment of decreasing swelling, alleviating pain and detoxification. Most of the current researches focused on the component analysis of Dai-Bai-Jie, but few researches studied on its antitumor and pharmacological effect. In this study, we incubated A549 cells with different concentrations of Dai-Bai-Jie. The cell proliferation experiment showed that the DaiBai-Jie solution inhibited the proliferation of A549 cells and caused cell apoptosis. In this work, we confirmed that Dai-Bai-Jie had an inhibitory effect on the proliferation and migration of non-small cell lung cancer A549, which may be used as a novel candidate of anti-tumor therapy for lung cancer patients.
2020, 31(2): 479-481
doi: 10.1016/j.cclet.2019.08.009
Abstract:
Ionophore can prominently improve the ion permeability of cell membrane and disrupt cellular ion homeostasis. Most studies regarding ionophore facilitating ion transmembrane transport focus on artificial liquid-liquid interfaces, which have large difference from the actual environment of cell membrane. Here, we construct a supported lipid bilayer on a gold nanoparticles film modified ZnSe prism as an appropriate model of cell membrane to investigate the dynamic of the ion transport facilitated by ionophore using surface enhanced infrared absorption spectroscopy (SEIRAS). We find that the ion transmembrane transport consists of two steps: The ion transmembrane transport starts with the association/disassociation between ion and ionophore at the edge of lipid bilayer; The second step is the transfer of ion-ionophore complex across lipid bilayer. Our results show that the complex transfer across the lipid bilayer is the rate determining step.
Ionophore can prominently improve the ion permeability of cell membrane and disrupt cellular ion homeostasis. Most studies regarding ionophore facilitating ion transmembrane transport focus on artificial liquid-liquid interfaces, which have large difference from the actual environment of cell membrane. Here, we construct a supported lipid bilayer on a gold nanoparticles film modified ZnSe prism as an appropriate model of cell membrane to investigate the dynamic of the ion transport facilitated by ionophore using surface enhanced infrared absorption spectroscopy (SEIRAS). We find that the ion transmembrane transport consists of two steps: The ion transmembrane transport starts with the association/disassociation between ion and ionophore at the edge of lipid bilayer; The second step is the transfer of ion-ionophore complex across lipid bilayer. Our results show that the complex transfer across the lipid bilayer is the rate determining step.
2020, 31(2): 482-486
doi: 10.1016/j.cclet.2019.07.065
Abstract:
Thiophonate-methyl (TPM) is one of fungicides and pesticides widely used in agriculture field. However, the residue of its benzimidazole (BZD) metabolites in related agricultural products poses a potential risk to consumers. In this paper, nickel oxide nanoparticle-deposited silica (SiO2@NiO) composite was used for the selective enrichment and purification of TPM's BZD metabolites in celery cabbage sprayed with TPM. Meanwhile, high-performance liquid chromatography coupled with precursor ion scan-mass spectrometry (HPLC-PIS-MS) and high-resolution MS/MS analysis (HR-MS/MS) was utilized for their qualitative and quantitative analysis. Twenty-one potential TPM's BZD metabolites were found and four of them were identified. One metabolite was discovered for the first time. Besides, a robust and sensitive quantitative method was developed with good linearities (R2 > 0.9972) within a wide range of 10.00-1000 ng/g. The detection limits of three known TPM's metabolites were within the range of 3.20-4.90 ng/g. Relative standard deviations (RSDs) of intra-day and inter-day precisions were less than 18.3%, which showed perfect reproducibility. The method was successfully applied to monitoring TPM's BZD metabolites in celery cabbage sprayed with TPM and the concentration versus time curves of TPM's metabolites in celery cabbage were plotted. This method is expected to be used to monitor BZD residues in various fruits and vegetables.
Thiophonate-methyl (TPM) is one of fungicides and pesticides widely used in agriculture field. However, the residue of its benzimidazole (BZD) metabolites in related agricultural products poses a potential risk to consumers. In this paper, nickel oxide nanoparticle-deposited silica (SiO2@NiO) composite was used for the selective enrichment and purification of TPM's BZD metabolites in celery cabbage sprayed with TPM. Meanwhile, high-performance liquid chromatography coupled with precursor ion scan-mass spectrometry (HPLC-PIS-MS) and high-resolution MS/MS analysis (HR-MS/MS) was utilized for their qualitative and quantitative analysis. Twenty-one potential TPM's BZD metabolites were found and four of them were identified. One metabolite was discovered for the first time. Besides, a robust and sensitive quantitative method was developed with good linearities (R2 > 0.9972) within a wide range of 10.00-1000 ng/g. The detection limits of three known TPM's metabolites were within the range of 3.20-4.90 ng/g. Relative standard deviations (RSDs) of intra-day and inter-day precisions were less than 18.3%, which showed perfect reproducibility. The method was successfully applied to monitoring TPM's BZD metabolites in celery cabbage sprayed with TPM and the concentration versus time curves of TPM's metabolites in celery cabbage were plotted. This method is expected to be used to monitor BZD residues in various fruits and vegetables.
2020, 31(2): 487-493
doi: 10.1016/j.cclet.2019.04.014
Abstract:
Carbon dots (CDs) with multi-color emissive properties and a high photoluminescent quantum yield (PLQY) have attracted great attention recently due to their potential applications in chemical, environmental, biological and photo-electronic fields. Solvent-dependent effect in photoluminescence provides a facial and effective approach to tune the emission of CDs. In this study, green emissive nitrogen-doped carbon dots (N-CDs) are synthesized from p-hydroquinone and ethylenediamine through a simple hydrothermal method. The as-prepared N-CDs possess a robust excitation-independent green luminescence and a high PLQYof up to 15.9%. Further spectroscopic characterization indicates that the high PLQY is achieved by the balance of nitrogen doping states and the surface passivation extent in CDs. The N-CDs also exhibit solvent-dependent multi-color emissive property and distinct PLQY in different solvents (the maximum can reach up to 25.3%). Furthermore, the as-prepared N-CDs are applied as fluorescence probes to detect acetone and H2O2 in water. This method has exhibited a low detection limit of acetone (less than 0.1%) and a quick and linear response to the H2O2 with the concentration from 0 to 120 μmol/L. This work broadens the knowledge of applying CDs as probes in the bio and chemical sensing fields.
Carbon dots (CDs) with multi-color emissive properties and a high photoluminescent quantum yield (PLQY) have attracted great attention recently due to their potential applications in chemical, environmental, biological and photo-electronic fields. Solvent-dependent effect in photoluminescence provides a facial and effective approach to tune the emission of CDs. In this study, green emissive nitrogen-doped carbon dots (N-CDs) are synthesized from p-hydroquinone and ethylenediamine through a simple hydrothermal method. The as-prepared N-CDs possess a robust excitation-independent green luminescence and a high PLQYof up to 15.9%. Further spectroscopic characterization indicates that the high PLQY is achieved by the balance of nitrogen doping states and the surface passivation extent in CDs. The N-CDs also exhibit solvent-dependent multi-color emissive property and distinct PLQY in different solvents (the maximum can reach up to 25.3%). Furthermore, the as-prepared N-CDs are applied as fluorescence probes to detect acetone and H2O2 in water. This method has exhibited a low detection limit of acetone (less than 0.1%) and a quick and linear response to the H2O2 with the concentration from 0 to 120 μmol/L. This work broadens the knowledge of applying CDs as probes in the bio and chemical sensing fields.
2020, 31(2): 494-500
doi: 10.1016/j.cclet.2019.04.048
Abstract:
Nowadays, tremendous researches have been focused on the core-shell lipid-polymer nanoparticles (LPNs) due to the advantages of both liposomes and polymer nanoparticles. In this work, LPNs were applied to encapsulate brinzolamide (Brz-LPNs) for achieving sustained drug release, improving drug corneal permeation and enhancing drug topical therapeutic effect. The structure of Brz-LPNs was composed of poly(lactic-co-glycolic) acid (PLGA) nanocore which encapsulated Brz (Brz-NPs) and lipid shell around the core. Brz-LPNs were prepared by a modified thin-film dispersion method. With the parameters optimization of Brz-LPNs, optimal Brz-LPNs showed an average particle size of 151.23±1.64 nm with a high encapsulation efficiency (EE) of 86.7%±2.28%. The core-shell structure of Brz-LPNs were confirmed by transmission electronic microscopy (TEM). Fourier transformed infrared spectra (FTIR) analysis proved that Brz was successfully entrapped into Brz-LPNs. Brz-LPNs exhibited obvious sustained release of Brz, compared with AZOPT® and Brz-LPs. Furthermore, the corneal accumulative permeability of Brz-LPNs significantly increased compared to the commercial available formulation (AZOPT®) in vitro. Moreover, Brz-LPNs (1 mg/mL Brz) showed a more sustained and effective intraocular pressure (IOP) reduction than Brz-LPs (1 mg/mL) and AZOPT® (10 mg/mL Brz) in vivo. In conclusion, Brz-LPNs, as promising ocular drug delivery systems, are well worth developing in the future for glaucoma treatment.
Nowadays, tremendous researches have been focused on the core-shell lipid-polymer nanoparticles (LPNs) due to the advantages of both liposomes and polymer nanoparticles. In this work, LPNs were applied to encapsulate brinzolamide (Brz-LPNs) for achieving sustained drug release, improving drug corneal permeation and enhancing drug topical therapeutic effect. The structure of Brz-LPNs was composed of poly(lactic-co-glycolic) acid (PLGA) nanocore which encapsulated Brz (Brz-NPs) and lipid shell around the core. Brz-LPNs were prepared by a modified thin-film dispersion method. With the parameters optimization of Brz-LPNs, optimal Brz-LPNs showed an average particle size of 151.23±1.64 nm with a high encapsulation efficiency (EE) of 86.7%±2.28%. The core-shell structure of Brz-LPNs were confirmed by transmission electronic microscopy (TEM). Fourier transformed infrared spectra (FTIR) analysis proved that Brz was successfully entrapped into Brz-LPNs. Brz-LPNs exhibited obvious sustained release of Brz, compared with AZOPT® and Brz-LPs. Furthermore, the corneal accumulative permeability of Brz-LPNs significantly increased compared to the commercial available formulation (AZOPT®) in vitro. Moreover, Brz-LPNs (1 mg/mL Brz) showed a more sustained and effective intraocular pressure (IOP) reduction than Brz-LPs (1 mg/mL) and AZOPT® (10 mg/mL Brz) in vivo. In conclusion, Brz-LPNs, as promising ocular drug delivery systems, are well worth developing in the future for glaucoma treatment.
2020, 31(2): 501-504
doi: 10.1016/j.cclet.2019.04.041
Abstract:
A straightforward coassembly strategy was developed for the preparation of polymeric nanoparticles driving by the intermolecular hydrogen bond between neutral poly(2-methyl-2-oxaozline) (PMeOx), tannic acid (TA) and doxorubicin hydrochloride (Dox). The occurrence of the hydrogen-bonding amongst the different functionalities within the formed nanoparticles was verified by infrared (IR) spectroscopy. Scanning electron microscopy (SEM), dynamic light scattering (DLS), UV-vis absorption and photoluminescent measurements indicated the rapid formation of uniform and water dispersible/stable nanoparticles. The relative poor stability of PMeOx-TA-Dox in fetal bovine serum (FBS) solution enabled the rapid separation of Dox and PMeOx-TA, facilitating the release of Dox and its entrance into cellular nuclei as revealed by confocal laser scanning microscopy (CLSM). The presented strategy may provide an efficient alternative for the construction of multifunctional nanomedicines.
A straightforward coassembly strategy was developed for the preparation of polymeric nanoparticles driving by the intermolecular hydrogen bond between neutral poly(2-methyl-2-oxaozline) (PMeOx), tannic acid (TA) and doxorubicin hydrochloride (Dox). The occurrence of the hydrogen-bonding amongst the different functionalities within the formed nanoparticles was verified by infrared (IR) spectroscopy. Scanning electron microscopy (SEM), dynamic light scattering (DLS), UV-vis absorption and photoluminescent measurements indicated the rapid formation of uniform and water dispersible/stable nanoparticles. The relative poor stability of PMeOx-TA-Dox in fetal bovine serum (FBS) solution enabled the rapid separation of Dox and PMeOx-TA, facilitating the release of Dox and its entrance into cellular nuclei as revealed by confocal laser scanning microscopy (CLSM). The presented strategy may provide an efficient alternative for the construction of multifunctional nanomedicines.
2020, 31(2): 505-508
doi: 10.1016/j.cclet.2019.04.049
Abstract:
Over the past two decades, layer-by-layer (LbL) assembly of micro/nanocapsules has been of interest for the investigation of bio-nano interactions to explore bio-applications, such as drug delivery. The choice of an appropriate template that can be easily dissolved under mild conditions is one of the challenges for the assembly of LbL capsules. Herein, we report the engineering of LbL capsules with tunable morphologies using cuprous oxide (Cu2O) particles as templates. Cu2O particles with cubic, tetradecahedral or spherical morphologies were synthesized via hydrothermal processes, which can be dissolved under mild condition (e.g., sodium thiosulfate solution). The influence of capsule morphologies on cell association was investigated, which indicates that LbL capsules with cubic geometry promoted cell association up to 4 and 9-fold than tetradecahedral and spherical capsules, respectively. The reported method provides a new avenue for the assembly of LbL capsules with different morphologies, which has the potential for better understanding of biological interactions of LbL capsules.
Over the past two decades, layer-by-layer (LbL) assembly of micro/nanocapsules has been of interest for the investigation of bio-nano interactions to explore bio-applications, such as drug delivery. The choice of an appropriate template that can be easily dissolved under mild conditions is one of the challenges for the assembly of LbL capsules. Herein, we report the engineering of LbL capsules with tunable morphologies using cuprous oxide (Cu2O) particles as templates. Cu2O particles with cubic, tetradecahedral or spherical morphologies were synthesized via hydrothermal processes, which can be dissolved under mild condition (e.g., sodium thiosulfate solution). The influence of capsule morphologies on cell association was investigated, which indicates that LbL capsules with cubic geometry promoted cell association up to 4 and 9-fold than tetradecahedral and spherical capsules, respectively. The reported method provides a new avenue for the assembly of LbL capsules with different morphologies, which has the potential for better understanding of biological interactions of LbL capsules.
2020, 31(2): 509-512
doi: 10.1016/j.cclet.2019.04.060
Abstract:
Kerogen is known as an important organic part for absorbing and forming shale gas whose absorption function, especially mechanical and tribological properties, has not been fully revealed. Here, we use Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis to reveal the chemical structure of kerogen. We report the first study of the adhesion and friction behavior of kerogen using atomic force microscope (AFM) Nanoman technology. Our finding reveals the friction of kerogen is decreased at higher pressure while is inhibited at increased temperature, and friction decreases logarithmically as the sliding speed increases. The weakened of Al-O linkage at high temperature have great influence on the decrease of friction forces between kerogen and alumina pellet. This finding lays the mechanism for understanding the dynamic adhesion behavior of kerogen in frictions, therefore attracting increasing interests from scientists, researchers, petroleum engineers and investors.
Kerogen is known as an important organic part for absorbing and forming shale gas whose absorption function, especially mechanical and tribological properties, has not been fully revealed. Here, we use Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis to reveal the chemical structure of kerogen. We report the first study of the adhesion and friction behavior of kerogen using atomic force microscope (AFM) Nanoman technology. Our finding reveals the friction of kerogen is decreased at higher pressure while is inhibited at increased temperature, and friction decreases logarithmically as the sliding speed increases. The weakened of Al-O linkage at high temperature have great influence on the decrease of friction forces between kerogen and alumina pellet. This finding lays the mechanism for understanding the dynamic adhesion behavior of kerogen in frictions, therefore attracting increasing interests from scientists, researchers, petroleum engineers and investors.
2020, 31(2): 513-516
doi: 10.1016/j.cclet.2019.04.065
Abstract:
As an emerging 2D conjugated material, graphitic carbon nitride (CN) has attracted great research attention as important catalytic medium for transforming solar energy. Nanostructure modulation of CN is an effective way to improve catalytic activities and has been extensively investigated, but remains challenging due to complex processes, time consuming or low yield. Here, taking advantage of recent discovered good solvents for CN, a nanoprecipitation approach using poor solvents is proposed for preparation of CN nanoparticles (CN NPs). With simple processes of CN dissolution and precipitation, we can quickly synthesize CN NPs (~40 nm) with a yield of up to 50%, the highest one to the best of our knowledge. As an example of potential applications, the as-prepared CN NPs were applied to photocatalytic degradation of dyes with an evident boosted performance up to 2.5 times. This work would open a new way for batch preparation of nanostructured CN and pave its large-scale industrial applications.
As an emerging 2D conjugated material, graphitic carbon nitride (CN) has attracted great research attention as important catalytic medium for transforming solar energy. Nanostructure modulation of CN is an effective way to improve catalytic activities and has been extensively investigated, but remains challenging due to complex processes, time consuming or low yield. Here, taking advantage of recent discovered good solvents for CN, a nanoprecipitation approach using poor solvents is proposed for preparation of CN nanoparticles (CN NPs). With simple processes of CN dissolution and precipitation, we can quickly synthesize CN NPs (~40 nm) with a yield of up to 50%, the highest one to the best of our knowledge. As an example of potential applications, the as-prepared CN NPs were applied to photocatalytic degradation of dyes with an evident boosted performance up to 2.5 times. This work would open a new way for batch preparation of nanostructured CN and pave its large-scale industrial applications.
2020, 31(2): 517-520
doi: 10.1016/j.cclet.2019.05.005
Abstract:
The controllable synthesis of one-dimensional (1D) structural morphology of metal-organic frameworks (MOFs) is significant for its application in catalysis, sense and gas separation. In this communication, we report a simple and moderate synthetic strategy to obtain uniform HKUST-1 nanobelts (NBs) by using copper nanowires (Cu NWs) as a metal source as well as a template. The control experiments showed that synergy between metal dissolution rate and crystal formation plays a key role in the formation of nanobelts. Our study represents an attractive synthetic strategy of 1D MOFs-based material for applications.
The controllable synthesis of one-dimensional (1D) structural morphology of metal-organic frameworks (MOFs) is significant for its application in catalysis, sense and gas separation. In this communication, we report a simple and moderate synthetic strategy to obtain uniform HKUST-1 nanobelts (NBs) by using copper nanowires (Cu NWs) as a metal source as well as a template. The control experiments showed that synergy between metal dissolution rate and crystal formation plays a key role in the formation of nanobelts. Our study represents an attractive synthetic strategy of 1D MOFs-based material for applications.
2020, 31(2): 521-524
doi: 10.1016/j.cclet.2019.04.071
Abstract:
Two-dimensional mesoporous materials combing ultrathin nanosheet morphology with well-defined mesoporous structures, are now emerging and becoming increasingly important for their promising applications in energy storage, electronic devices, electrocatalysts and so on. Here, we synthesized a kind of polypyrrole-based two-dimensional mesoporous materials with uniform pore size, ultrathin thickness and high surface area. Serving for electrochemical NH3 sensor, they exhibited a fast response and high sensitivity. Therefore, our study would promote much interest in design of new materials for gas sensor applications.
Two-dimensional mesoporous materials combing ultrathin nanosheet morphology with well-defined mesoporous structures, are now emerging and becoming increasingly important for their promising applications in energy storage, electronic devices, electrocatalysts and so on. Here, we synthesized a kind of polypyrrole-based two-dimensional mesoporous materials with uniform pore size, ultrathin thickness and high surface area. Serving for electrochemical NH3 sensor, they exhibited a fast response and high sensitivity. Therefore, our study would promote much interest in design of new materials for gas sensor applications.
2020, 31(2): 525-529
doi: 10.1016/j.cclet.2019.04.070
Abstract:
Surface chemical properties of supports have an important influence on active sites and their catalytic behavior. Here, we fabricated a series of cobalt-based catalysts supported by carbon layer-coated ordered mesoporous silica (OMS) composites for higher alcohol synthesis (HAS). The carbon layers were derived from different sources and uniformly coated on the porous surface of OMS. Combined with the characterization results of carbonized catalysts, it is demonstrated that the carbon layer-coated supports significantly enhanced the metal dispersion and increased the ratio of Co2+ to Co0 sites, which further increased the CO conversion and alcohols selectivity. Moreover, it is found that the catalytic activity changed in line with the amount of defects and surface oxygenic groups of carbon layers, which resulted from the different carbon sources. The highest space time yield of C2+OH was 27.5 mmol gcat-1 h-1) obtained by the catalyst coated with glucose-derived carbon layer. But the carbon source is not the key factor influencing the distribution of Co-Co2+ dual sites and shows little effect on selectivity in HAS. These results may guide for further design of carbon supported catalysts.
Surface chemical properties of supports have an important influence on active sites and their catalytic behavior. Here, we fabricated a series of cobalt-based catalysts supported by carbon layer-coated ordered mesoporous silica (OMS) composites for higher alcohol synthesis (HAS). The carbon layers were derived from different sources and uniformly coated on the porous surface of OMS. Combined with the characterization results of carbonized catalysts, it is demonstrated that the carbon layer-coated supports significantly enhanced the metal dispersion and increased the ratio of Co2+ to Co0 sites, which further increased the CO conversion and alcohols selectivity. Moreover, it is found that the catalytic activity changed in line with the amount of defects and surface oxygenic groups of carbon layers, which resulted from the different carbon sources. The highest space time yield of C2+OH was 27.5 mmol gcat-1 h-1) obtained by the catalyst coated with glucose-derived carbon layer. But the carbon source is not the key factor influencing the distribution of Co-Co2+ dual sites and shows little effect on selectivity in HAS. These results may guide for further design of carbon supported catalysts.
2020, 31(2): 530-534
doi: 10.1016/j.cclet.2019.04.069
Abstract:
Developing low-cost and high performance catalysts to replace precious metal based catalysts for oxygen reduction reaction (ORR) is one of the most feasible ways to promote the commercial application of fuel cells. In this work, flower-like CoS and octahedral CoS2 are synthesized by a facile one-pot hydrothermal method without any adjunction of surfactants or follow-up thermolysis, their catalytic performance towards ORR in alkaline electrolyte are comparatively investigated. The results reveal that CoS2 outperforms CoS owing to the higher electron density around S-S bond of S22- in the crystal structure, which promotes the adsorption of oxygen on catalyst surface and facilitates the breakage of O-O bond in oxygen, leading to direct 4-electron transfer ORR. When CoS2 particles are dispersed on the surface of rGO with large surface area, their ORR performance could be further improved.
Developing low-cost and high performance catalysts to replace precious metal based catalysts for oxygen reduction reaction (ORR) is one of the most feasible ways to promote the commercial application of fuel cells. In this work, flower-like CoS and octahedral CoS2 are synthesized by a facile one-pot hydrothermal method without any adjunction of surfactants or follow-up thermolysis, their catalytic performance towards ORR in alkaline electrolyte are comparatively investigated. The results reveal that CoS2 outperforms CoS owing to the higher electron density around S-S bond of S22- in the crystal structure, which promotes the adsorption of oxygen on catalyst surface and facilitates the breakage of O-O bond in oxygen, leading to direct 4-electron transfer ORR. When CoS2 particles are dispersed on the surface of rGO with large surface area, their ORR performance could be further improved.
2020, 31(2): 535-538
doi: 10.1016/j.cclet.2019.04.038
Abstract:
ZnO-CeO2/SBA-15 catalysts were prepared by two kinds of solid-state grinding method and used for the production of 1, 3-butadiene (1, 3-BD) from ethanol. A mixture of SBA-15 (with or without organic template) and metal precursors were ground in solid-state. The obtained catalysts were characterized by TG, N2 adsorption-desorption, TEM, XRD, Py-FTIR and NH3-TPD techniques. Superior dispersion of metal oxides and more exposed acid sites were achieved on the catalyst 10Zn1Ce5-AS with the presence of organic template in SBA-15 during the solid-state grinding process. The catalytic performance was evaluated in a fixed-bed reactor and a 1, 3-butadiene selectivity of as high as 45% is achieved. This is attributed to the coupling effect of Zn and Ce species in the mesopores of SBA-15, in which Zn promotes ethanol dehydrogenation and Ce enhances aldol-condensation, respectively. Additionally, solvent-free method inspires new catalyst synthesis strategy for the production of 1, 3-butadiene from ethanol.
ZnO-CeO2/SBA-15 catalysts were prepared by two kinds of solid-state grinding method and used for the production of 1, 3-butadiene (1, 3-BD) from ethanol. A mixture of SBA-15 (with or without organic template) and metal precursors were ground in solid-state. The obtained catalysts were characterized by TG, N2 adsorption-desorption, TEM, XRD, Py-FTIR and NH3-TPD techniques. Superior dispersion of metal oxides and more exposed acid sites were achieved on the catalyst 10Zn1Ce5-AS with the presence of organic template in SBA-15 during the solid-state grinding process. The catalytic performance was evaluated in a fixed-bed reactor and a 1, 3-butadiene selectivity of as high as 45% is achieved. This is attributed to the coupling effect of Zn and Ce species in the mesopores of SBA-15, in which Zn promotes ethanol dehydrogenation and Ce enhances aldol-condensation, respectively. Additionally, solvent-free method inspires new catalyst synthesis strategy for the production of 1, 3-butadiene from ethanol.
2020, 31(2): 539-542
doi: 10.1016/j.cclet.2019.07.037
Abstract:
The toxic organic dye contaminants in wastewater are extremely harmful to the ecosystem. Surface enhanced Raman scattering (SERS) is a technique with high sensitivity and chemical specificity which fulfills the requirements for monitoring dye contaminants in wastewater. However, as one of the common dye contaminants, methyl orange (MO) has very weak affinity to metallic surfaces and is difficult to be detected by SERS at low concentrations. Therefore, a new type of SERS substrate with Ag nanoparticle monolayer functionalized by mono-6-deoxy-6-thio-β-cyclodextrin (β-CD-SH) was prepared to efficiently capture and detect MO in wastewater with a limit of detection of 5×10-7 mol/L. The hydrophobic cavity of β-CD is responsible for the efficient trap and enrichment of MO on the Ag NPs surface, achieving a strong SERS signal of MO at low concentrations and at different pH values. This study provides new insight into designing a well-performed adsorbent for the capture and detection of organic contaminants.
The toxic organic dye contaminants in wastewater are extremely harmful to the ecosystem. Surface enhanced Raman scattering (SERS) is a technique with high sensitivity and chemical specificity which fulfills the requirements for monitoring dye contaminants in wastewater. However, as one of the common dye contaminants, methyl orange (MO) has very weak affinity to metallic surfaces and is difficult to be detected by SERS at low concentrations. Therefore, a new type of SERS substrate with Ag nanoparticle monolayer functionalized by mono-6-deoxy-6-thio-β-cyclodextrin (β-CD-SH) was prepared to efficiently capture and detect MO in wastewater with a limit of detection of 5×10-7 mol/L. The hydrophobic cavity of β-CD is responsible for the efficient trap and enrichment of MO on the Ag NPs surface, achieving a strong SERS signal of MO at low concentrations and at different pH values. This study provides new insight into designing a well-performed adsorbent for the capture and detection of organic contaminants.
2020, 31(2): 543-546
doi: 10.1016/j.cclet.2019.08.031
Abstract:
Sulfamethazine (SMZ) is an important sulfonamide antibiotic. Although the concentration in the environment is small, it is harmful. The drug residues can be transferred, transformed or accumulated, affecting the growth of animals and plants. In this study, the integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR) were constructed to investigate the performance and degradation mechanism of SMZ. The addition of SMZ had a significant impact on the removal of the chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N). The optimal operating conditions were hydraulic retention time (HRT) at 10 h and solid retention time (SRT) at 80 d, respectively. On this basis, the effects of different SMZ concentrations on nutrient removal, degradation, and sludge characteristics were compared. The removal efficiency of SMZ increased with the increase of SMZ concentration. The maximum removal rate was as high as 87%. The SMZ dosage also had an obvious effect on sludge characteristics. As the SMZ concentration increased, the extracellular polymer substances (EPS) concentration and the membrane resistance both decreased, which were beneficial for the reduction of membrane fouling. Finally, seven kinds of SMZ biodegradation intermediates were identified, and the possible degradation pathways were speculated. The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent. The relative abundance of Bacteroidetes, Actinobacteria, Saccharibacteria and Nitrospirae increased at the phylum level. Sphingobacteria and Betaproteobacteria became dominant species at the class level. The relative abundance of norankp-Saccharibacteria and Nitrospirae increased significantly, and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.
Sulfamethazine (SMZ) is an important sulfonamide antibiotic. Although the concentration in the environment is small, it is harmful. The drug residues can be transferred, transformed or accumulated, affecting the growth of animals and plants. In this study, the integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR) were constructed to investigate the performance and degradation mechanism of SMZ. The addition of SMZ had a significant impact on the removal of the chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N). The optimal operating conditions were hydraulic retention time (HRT) at 10 h and solid retention time (SRT) at 80 d, respectively. On this basis, the effects of different SMZ concentrations on nutrient removal, degradation, and sludge characteristics were compared. The removal efficiency of SMZ increased with the increase of SMZ concentration. The maximum removal rate was as high as 87%. The SMZ dosage also had an obvious effect on sludge characteristics. As the SMZ concentration increased, the extracellular polymer substances (EPS) concentration and the membrane resistance both decreased, which were beneficial for the reduction of membrane fouling. Finally, seven kinds of SMZ biodegradation intermediates were identified, and the possible degradation pathways were speculated. The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent. The relative abundance of Bacteroidetes, Actinobacteria, Saccharibacteria and Nitrospirae increased at the phylum level. Sphingobacteria and Betaproteobacteria became dominant species at the class level. The relative abundance of norankp-Saccharibacteria and Nitrospirae increased significantly, and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.
2020, 31(2): 547-550
doi: 10.1016/j.cclet.2019.09.051
Abstract:
Constructing a Z-scheme is a significant approach to improve the separation of photogenerated carriers for effective organic pollutant degradation. Herein, a BiVO4/ZnIn2S4 (BZ) Z-scheme composite was successfully synthesized, and applied to photodegrade methyl orange (MO) irradiated by a LED lamp. Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range. The detailed characterizations, including surface morphology, elements valence state, and photocurrent performance, demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction. Benefiting from the excellent photocatalytic characteristics, the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min-1, which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4, respectively. Furthermore, the BZ hybrid materials indicated a well photo-stability in the four recycling tests.
Constructing a Z-scheme is a significant approach to improve the separation of photogenerated carriers for effective organic pollutant degradation. Herein, a BiVO4/ZnIn2S4 (BZ) Z-scheme composite was successfully synthesized, and applied to photodegrade methyl orange (MO) irradiated by a LED lamp. Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range. The detailed characterizations, including surface morphology, elements valence state, and photocurrent performance, demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction. Benefiting from the excellent photocatalytic characteristics, the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min-1, which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4, respectively. Furthermore, the BZ hybrid materials indicated a well photo-stability in the four recycling tests.
2020, 31(2): 551-553
doi: 10.1016/j.cclet.2019.04.062
Abstract:
X-ray imaging functionalization of biodegradable polyesters is a great demand and challenge in biomedical applications. In this work, a strategy of in-chain functionalization through the combination of ring opening copolymerization and oxime "Click" postfunctionalization was developed towards X-ray opaque polylactide copolymers. A functionalized cyclic carbonate was first synthesized and used as comonomer of polylactide copolymers, which were subjected to postfunctionalization of oxime "Click" reaction towards iodinated polylactide copolymers. The chemical structure and physical properties of the target products were traced and confirmed. In vitro cytotoxicity evaluation with 3T3-Swiss albino by Alamar blue demonstrated a low cytotoxicity. The X-ray radiopacity was analyzed by Micro-CT and quantified by Hounsfield Units value, which could be tailorable by the feedstock. It is a promising X-ray visible implantable biomaterial in biomedical applications.
X-ray imaging functionalization of biodegradable polyesters is a great demand and challenge in biomedical applications. In this work, a strategy of in-chain functionalization through the combination of ring opening copolymerization and oxime "Click" postfunctionalization was developed towards X-ray opaque polylactide copolymers. A functionalized cyclic carbonate was first synthesized and used as comonomer of polylactide copolymers, which were subjected to postfunctionalization of oxime "Click" reaction towards iodinated polylactide copolymers. The chemical structure and physical properties of the target products were traced and confirmed. In vitro cytotoxicity evaluation with 3T3-Swiss albino by Alamar blue demonstrated a low cytotoxicity. The X-ray radiopacity was analyzed by Micro-CT and quantified by Hounsfield Units value, which could be tailorable by the feedstock. It is a promising X-ray visible implantable biomaterial in biomedical applications.
2020, 31(2): 554-558
doi: 10.1016/j.cclet.2019.05.008
Abstract:
(C6H14N2)[NH4(ClO4)3] is a newly developed porous hybrid inorganic-organic framework material with easy access and excellent detonation performances, however, its thermal properties is still unclear and severely hampered further applications. In this study, thermal behaviors and non-isothermal decomposition reaction kinetics of (C6H14N2)[NH4(ClO4)3] were investigated systematically by the combination of differential scanning calorimetry (DSC) and simultaneous thermal analysis methods. In-situ FTIR spectroscopy technology was applied for investigation of the structure changes of (C6H14N2)[NH4(ClO4)3] and some selected referents for better understanding of interactions between different components during the heating process. Experiment results indicated that the novel molecular perovskite structure renders (C6H14N2)[NH4(ClO4)3] better thermal stability than most of currently used energetic materials. Under high temperatures, the stability of the cage skeleton constructed by NH4+ and ClO4- ionsdetermined the decomposition process rather than organic moiety confined in the skeleton. The simple synthetic method, good detonation performances and excellent thermal properties make (C6H14N2)[NH4(ClO4)3] an ideal candidate for the preparation of advanced explosives and propellants.
(C6H14N2)[NH4(ClO4)3] is a newly developed porous hybrid inorganic-organic framework material with easy access and excellent detonation performances, however, its thermal properties is still unclear and severely hampered further applications. In this study, thermal behaviors and non-isothermal decomposition reaction kinetics of (C6H14N2)[NH4(ClO4)3] were investigated systematically by the combination of differential scanning calorimetry (DSC) and simultaneous thermal analysis methods. In-situ FTIR spectroscopy technology was applied for investigation of the structure changes of (C6H14N2)[NH4(ClO4)3] and some selected referents for better understanding of interactions between different components during the heating process. Experiment results indicated that the novel molecular perovskite structure renders (C6H14N2)[NH4(ClO4)3] better thermal stability than most of currently used energetic materials. Under high temperatures, the stability of the cage skeleton constructed by NH4+ and ClO4- ionsdetermined the decomposition process rather than organic moiety confined in the skeleton. The simple synthetic method, good detonation performances and excellent thermal properties make (C6H14N2)[NH4(ClO4)3] an ideal candidate for the preparation of advanced explosives and propellants.
2020, 31(2): 559-564
doi: 10.1016/j.cclet.2019.04.055
Abstract:
In this paper, we introduced a novel method to prepare the few-layer nitrogen-doped graphene (FNG) from expandable graphite with melamine. The super-capacitive properties of FNG were thoroughly characterized by a three-electrode system, and the results showed the FNG electrode achieved a specific capacitance as high as 83.8 mF/cm2 together with excellent cycling stability. This method could be a novel approach to combine the pseudo-capacitors and electric double layer capacitors.
In this paper, we introduced a novel method to prepare the few-layer nitrogen-doped graphene (FNG) from expandable graphite with melamine. The super-capacitive properties of FNG were thoroughly characterized by a three-electrode system, and the results showed the FNG electrode achieved a specific capacitance as high as 83.8 mF/cm2 together with excellent cycling stability. This method could be a novel approach to combine the pseudo-capacitors and electric double layer capacitors.
2020, 31(2): 565-569
doi: 10.1016/j.cclet.2019.05.014
Abstract:
Nitrogen doping is a promising way to modulate the electrical properties of graphene to realize graphene-based electronics and promise fascinating properties and applications. Herein, we report a method to noncovalently assembly titanium(Ⅳ) bis(ammoniumlactato) dihydroxide (Ti complex) on nitrogen-doped graphene to create a reliable hybrids which can be used as a reversible chemical induced switching. As the adsorption and desorption of Ti complex in sequential treatments, the conductance of the nitrogen-doped graphene transistors was finely modulated. Control experiments with pristine graphene clearly demonstrated the important effort of the nitrogen in this chemical sensor. Under optimized conditions, nitrogen-doped graphene transistors open up new ways to develop multifunctional devices with high sensitivity.
Nitrogen doping is a promising way to modulate the electrical properties of graphene to realize graphene-based electronics and promise fascinating properties and applications. Herein, we report a method to noncovalently assembly titanium(Ⅳ) bis(ammoniumlactato) dihydroxide (Ti complex) on nitrogen-doped graphene to create a reliable hybrids which can be used as a reversible chemical induced switching. As the adsorption and desorption of Ti complex in sequential treatments, the conductance of the nitrogen-doped graphene transistors was finely modulated. Control experiments with pristine graphene clearly demonstrated the important effort of the nitrogen in this chemical sensor. Under optimized conditions, nitrogen-doped graphene transistors open up new ways to develop multifunctional devices with high sensitivity.
2020, 31(2): 463-467
doi: 10.1016/j.cclet.2019.06.024
Abstract:
A simple and feasible potentiometric immunosensing platform based on enzymatic biocatalytic precipitation technique was designed for the sensitive detection of thyroid-stimulating hormone (TSH; a typical kind of biomarkers for thyroid carcinoma), using horseradish peroxidase (HRP)-loaded liposome for the signal amplification. To construct such an assay system, a sandwich-type immunoreaction was readily carried out on monoclonal anti-TSH capture antibody-coated electrode by using polyclonal antiTSH secondary antibody-conjugated HRP-loaded liposome. Accompanying the formation of sandwichtype immunocomplex, the carried liposome was lysed through the added Triton X-100 to release the entrapped HRP molecules, which catalyzed the oxidation of 4-chloro-1-naphthol to produce an insoluble and uncharged organic precipitation on the electrode surface, thereby causing the change of the local electrical potential. Two labeling protocols with and without the liposome were investigated for detection of target TSH, improved analytical features were achieved with HRP-entrapped liposome. Under optimal conditions, the potentiometric immunosensor had good responses for TSH detection within the linear range of 0.01-30 μIU/mL at a detection limit of 0.0067 μIU/mL. Good reproducibility, high specificity and long-time stability were acquired during the assay procedure. Importantly, a wellmatched accuracy between the potentiometric immunosensor and commercial human TSH ELISA kit was gave for the analysis of human serum samples.
A simple and feasible potentiometric immunosensing platform based on enzymatic biocatalytic precipitation technique was designed for the sensitive detection of thyroid-stimulating hormone (TSH; a typical kind of biomarkers for thyroid carcinoma), using horseradish peroxidase (HRP)-loaded liposome for the signal amplification. To construct such an assay system, a sandwich-type immunoreaction was readily carried out on monoclonal anti-TSH capture antibody-coated electrode by using polyclonal antiTSH secondary antibody-conjugated HRP-loaded liposome. Accompanying the formation of sandwichtype immunocomplex, the carried liposome was lysed through the added Triton X-100 to release the entrapped HRP molecules, which catalyzed the oxidation of 4-chloro-1-naphthol to produce an insoluble and uncharged organic precipitation on the electrode surface, thereby causing the change of the local electrical potential. Two labeling protocols with and without the liposome were investigated for detection of target TSH, improved analytical features were achieved with HRP-entrapped liposome. Under optimal conditions, the potentiometric immunosensor had good responses for TSH detection within the linear range of 0.01-30 μIU/mL at a detection limit of 0.0067 μIU/mL. Good reproducibility, high specificity and long-time stability were acquired during the assay procedure. Importantly, a wellmatched accuracy between the potentiometric immunosensor and commercial human TSH ELISA kit was gave for the analysis of human serum samples.
