Login In
2019 Volume 36 Issue 5
2019, 36(5): 489-499
doi: 10.11944/j.issn.1000-0518.2019.05.180253
Abstract:
As the intermediate product of protein hydrolysis, peptides are synthesized through the polymerization of α-amino acids. Given the great biocompatibility and surface plasmon resonance(SPR) of gold nanoparticles(AuNPs), biosensors based on the peptide-AuNPs system have attracted the attention of many scientists. In this review, the biosensing research and application of the peptide-AuNPs complexes are summarized, including the preparation and properties of peptides and AuNPs, the synthesis of peptide-AuNPs and the application in biosensing.
As the intermediate product of protein hydrolysis, peptides are synthesized through the polymerization of α-amino acids. Given the great biocompatibility and surface plasmon resonance(SPR) of gold nanoparticles(AuNPs), biosensors based on the peptide-AuNPs system have attracted the attention of many scientists. In this review, the biosensing research and application of the peptide-AuNPs complexes are summarized, including the preparation and properties of peptides and AuNPs, the synthesis of peptide-AuNPs and the application in biosensing.
2019, 36(5): 500-508
doi: 10.11944/j.issn.1000-0518.2019.05.180284
Abstract:
Chitosan oligosaccharide thiosemicarbazide was prepared in one-pot. Then chitosan oligosaccharide thiosemicarbazone was synthesized by the reaction of chitosan thiosemicarbazide with 2-pyridinecarboxaldehyde. Chitosan oligosaccharide thiosemicarbazone Cu(Ⅱ) complex was thus obtained by the reaction of chitosan thiosemicarbazide with Cu(Ⅱ) salt. The structure of the synthesized compounds was characterized by infrared(IR) spectroscopy, ultraviolet-visible(UV-Vis) spectroscopy, nuclear magnetic resonance(NMR), inductively coupled plasma(ICP), and thermogravimetry-differential thermal analysis(TG-DTA). The antifungal behaviors of chitosan oligosaccharide and its derivatives against three crop-threatening pathogenic fungi:Phytophthora capsici (P.capsici), Phytophthora nicotianae (P.nicotianae), Fusarium graminearum (F.graminearum) were investigated by mycelial growth rate method in vitro. The results show that the inhibitory index of chitosan thiosemicarbazone Cu(Ⅱ) complex against P.capsici, P.nicotianae, F.graminearum is 74.19%, 56.60%, 66.60%, respectively, and is higher than those observed with chitosan.
Chitosan oligosaccharide thiosemicarbazide was prepared in one-pot. Then chitosan oligosaccharide thiosemicarbazone was synthesized by the reaction of chitosan thiosemicarbazide with 2-pyridinecarboxaldehyde. Chitosan oligosaccharide thiosemicarbazone Cu(Ⅱ) complex was thus obtained by the reaction of chitosan thiosemicarbazide with Cu(Ⅱ) salt. The structure of the synthesized compounds was characterized by infrared(IR) spectroscopy, ultraviolet-visible(UV-Vis) spectroscopy, nuclear magnetic resonance(NMR), inductively coupled plasma(ICP), and thermogravimetry-differential thermal analysis(TG-DTA). The antifungal behaviors of chitosan oligosaccharide and its derivatives against three crop-threatening pathogenic fungi:Phytophthora capsici (P.capsici), Phytophthora nicotianae (P.nicotianae), Fusarium graminearum (F.graminearum) were investigated by mycelial growth rate method in vitro. The results show that the inhibitory index of chitosan thiosemicarbazone Cu(Ⅱ) complex against P.capsici, P.nicotianae, F.graminearum is 74.19%, 56.60%, 66.60%, respectively, and is higher than those observed with chitosan.
2019, 36(5): 509-514
doi: 10.11944/j.issn.1000-0518.2019.05.180331
Abstract:
In order to overcome the low yield, long reaction time, and the difficult product separation in current methods, 2, 3, 4, 6-O-tetraacetyl-α-D-glucopyranosyl bromide(1) was firstly prepared from β-D-glucose and acetyl bromide via acetylation and bromination. Then, five kinds of 4-formylphenyl(2, 3, 4, 6-O-tetraacetyl)-β-D-glucoside derivatives were obtained via glycosylation between intermediate 1 and 4-hydroxybenzaldhyde derivatives. The yields of products reached 61%~69% when 10%(mass fraction) NaOH solution and tris(3, 6-dioxaheptyl)amine(TDA-1) were used as base and phase transfer catalyst, respectively. The obtained compounds were confirmed by nuclear magnetic resonance(NMR). This method shows advantages in high yield, mild conditions and simple operation.
In order to overcome the low yield, long reaction time, and the difficult product separation in current methods, 2, 3, 4, 6-O-tetraacetyl-α-D-glucopyranosyl bromide(1) was firstly prepared from β-D-glucose and acetyl bromide via acetylation and bromination. Then, five kinds of 4-formylphenyl(2, 3, 4, 6-O-tetraacetyl)-β-D-glucoside derivatives were obtained via glycosylation between intermediate 1 and 4-hydroxybenzaldhyde derivatives. The yields of products reached 61%~69% when 10%(mass fraction) NaOH solution and tris(3, 6-dioxaheptyl)amine(TDA-1) were used as base and phase transfer catalyst, respectively. The obtained compounds were confirmed by nuclear magnetic resonance(NMR). This method shows advantages in high yield, mild conditions and simple operation.
2019, 36(5): 515-523
doi: 10.11944/j.issn.1000-0518.2019.05.180245
Abstract:
A series of Cr2O3 catalysts was prepared by a precipitation method and tested for the gas phase dehydrochlorination of 1, 1, 2-trichloroethane(TCE) to synthesize cis-1, 2-dichloroethylene(cis-DCE). X-ray diffraction(XRD), hydrogen temperature-programmed reduction(H2-TPR), ammonia temperature-programmed desorption(NH3-TPD) and X-ray photoelectron spectroscopy(XPS) were used to study the dehydrochlorination of TCE on Cr2O3 catalyst and its reaction mechanism. It is found that the conversion ratio of TCE on the catalysts decreases with the increase of the calcination temperature, while the selectivity to cis-DCE first increases and then decreases. The best performance is obtained on the catalyst calcined at 400℃, with a TCE conversion ratio of 70.8% and a cis-DCE selectivity of 90.0%. In addition, the areal specific reaction rate also first increases and then decreases with the increase of the calcination temperature, with the highest value being obtained on the catalysts calcined at 400℃(0.801×10-2 μmol/(s·m2). The catalytic behaviors of the catalysts are well related to their surface Cr2O3 species. Turnover frequencies(TOFs) calculated based on the surface acidity and the highest value being obtained on the catalysts calcined at 400℃(2.82×10-5 s-1) show that the oxidation states of the surface Cr species are important for the reaction and the Cr species with an average valence of 3.2 are appropriate for the reaction.
A series of Cr2O3 catalysts was prepared by a precipitation method and tested for the gas phase dehydrochlorination of 1, 1, 2-trichloroethane(TCE) to synthesize cis-1, 2-dichloroethylene(cis-DCE). X-ray diffraction(XRD), hydrogen temperature-programmed reduction(H2-TPR), ammonia temperature-programmed desorption(NH3-TPD) and X-ray photoelectron spectroscopy(XPS) were used to study the dehydrochlorination of TCE on Cr2O3 catalyst and its reaction mechanism. It is found that the conversion ratio of TCE on the catalysts decreases with the increase of the calcination temperature, while the selectivity to cis-DCE first increases and then decreases. The best performance is obtained on the catalyst calcined at 400℃, with a TCE conversion ratio of 70.8% and a cis-DCE selectivity of 90.0%. In addition, the areal specific reaction rate also first increases and then decreases with the increase of the calcination temperature, with the highest value being obtained on the catalysts calcined at 400℃(0.801×10-2 μmol/(s·m2). The catalytic behaviors of the catalysts are well related to their surface Cr2O3 species. Turnover frequencies(TOFs) calculated based on the surface acidity and the highest value being obtained on the catalysts calcined at 400℃(2.82×10-5 s-1) show that the oxidation states of the surface Cr species are important for the reaction and the Cr species with an average valence of 3.2 are appropriate for the reaction.
2019, 36(5): 524-531
doi: 10.11944/j.issn.1000-0518.2019.05.180296
Abstract:
Fourteen kinds of salicylaldehyde Schiff bases containing morpholinyl fragments are synthesized by the condensation reaction of 3-fluoro-4-morpholiniline and substituted salicylate and confirmed by nuclear magnetic resonance spectroscopy(NMR), Fourier transform infrared spectrometer(FTIR), liquid chromatography-mass spectrometer(LC-MS) and element analysis. The 1, 1-diphenyl-2-picrylhydrazyl(DPPH) radical quenching activities of these Schiff bases are also studied. The results show that all compounds show certain quenching activity of DPPH radicals at concentrations of 0.02 to 0.10 g/L. Among them, the compounds Ⅰd and Ⅰf show excellent properties. The activity of compound Ⅰd is between 30% and 55%, and the activity of compound Ⅰf is more than 50%. With the increase of the concentration of compounds Ⅰd, Ⅰh, Ⅰj and Ⅰn, the DPPH radical quenching activities increase.
Fourteen kinds of salicylaldehyde Schiff bases containing morpholinyl fragments are synthesized by the condensation reaction of 3-fluoro-4-morpholiniline and substituted salicylate and confirmed by nuclear magnetic resonance spectroscopy(NMR), Fourier transform infrared spectrometer(FTIR), liquid chromatography-mass spectrometer(LC-MS) and element analysis. The 1, 1-diphenyl-2-picrylhydrazyl(DPPH) radical quenching activities of these Schiff bases are also studied. The results show that all compounds show certain quenching activity of DPPH radicals at concentrations of 0.02 to 0.10 g/L. Among them, the compounds Ⅰd and Ⅰf show excellent properties. The activity of compound Ⅰd is between 30% and 55%, and the activity of compound Ⅰf is more than 50%. With the increase of the concentration of compounds Ⅰd, Ⅰh, Ⅰj and Ⅰn, the DPPH radical quenching activities increase.
2019, 36(5): 532-538
doi: 10.11944/j.issn.1000-0518.2019.05.180233
Abstract:
Polyurethane-acrylate/nano-SiO2(PUAS) composite emulsions were synthesized by in situ polymerization accompanying sol-gel process, in which the hydrolysis reaction and polymerization of monomers were accomplished at the same time. The properties and structure of the films and emulsion were characterized by a laser particle size analyzer, scanning electron microscopy(SEM) and transmission electron microscopy(TEM), etc. The results indicated that with the increase of the mass fraction of tetraethylorthosilicate(TEOS), the thermostability and the mechanical properties of the films were improved remarkably. When the mass fraction of TEOS was 8% in the PUAS composite emulsion, the water absorption of the obtained film was 2.1%, the tensile strength was 16.8 MPa, the Shore hardness was 94, and the temperature for the maximal thermal mass-loss rate was 416℃.
Polyurethane-acrylate/nano-SiO2(PUAS) composite emulsions were synthesized by in situ polymerization accompanying sol-gel process, in which the hydrolysis reaction and polymerization of monomers were accomplished at the same time. The properties and structure of the films and emulsion were characterized by a laser particle size analyzer, scanning electron microscopy(SEM) and transmission electron microscopy(TEM), etc. The results indicated that with the increase of the mass fraction of tetraethylorthosilicate(TEOS), the thermostability and the mechanical properties of the films were improved remarkably. When the mass fraction of TEOS was 8% in the PUAS composite emulsion, the water absorption of the obtained film was 2.1%, the tensile strength was 16.8 MPa, the Shore hardness was 94, and the temperature for the maximal thermal mass-loss rate was 416℃.
2019, 36(5): 539-547
doi: 10.11944/j.issn.1000-0518.2019.05.180286
Abstract:
The effect of poly(4-ethylphenol) antioxidant on the non-isothermal crystallization behavior of polypropylene(PP) was studied by differential scanning calorimetry(DSC) and X-ray powder diffractometry(XRD), respectively. The non-isothermal crystallization kinetics was studied by the Jeziorny method and the Mo method, and the activation energy was calculated by the Friedman method and the Kissinger method at the same time. The Hoffman-Lauritzen parameters of nucleation rate constant(Kg) and molecular diffusion activation energy(U*) are obtained from the relation of crystallization activity energy and average crystallization temperatures for PP and PP with (4-ethylphenol) antioxidant(PP-A) samples, and the fold surface free energy(σe) and the work of chain folding per molecule(q) are then calculated. The results show that the crystallization peak of PP-A moves to a lower temperature with the addition of antioxidant, and the crystallization half-peak width becomes broader, the semi-crystallization(t1/2) and the parameter F(T) reflecting the value of cooling rate chosen at unit crystallization time obtained by Mo method increase while the crystallization rate(Z) decreases. The negative crystallization activity energy becomes smaller at the same crystallization conversion rate, and the Hoffman-Lauritzen parameters of Kg, U*, σe and q increase. All the results indicate that poly(4-ethylphenol) antioxidant inhibits the crystallization of PP.
The effect of poly(4-ethylphenol) antioxidant on the non-isothermal crystallization behavior of polypropylene(PP) was studied by differential scanning calorimetry(DSC) and X-ray powder diffractometry(XRD), respectively. The non-isothermal crystallization kinetics was studied by the Jeziorny method and the Mo method, and the activation energy was calculated by the Friedman method and the Kissinger method at the same time. The Hoffman-Lauritzen parameters of nucleation rate constant(Kg) and molecular diffusion activation energy(U*) are obtained from the relation of crystallization activity energy and average crystallization temperatures for PP and PP with (4-ethylphenol) antioxidant(PP-A) samples, and the fold surface free energy(σe) and the work of chain folding per molecule(q) are then calculated. The results show that the crystallization peak of PP-A moves to a lower temperature with the addition of antioxidant, and the crystallization half-peak width becomes broader, the semi-crystallization(t1/2) and the parameter F(T) reflecting the value of cooling rate chosen at unit crystallization time obtained by Mo method increase while the crystallization rate(Z) decreases. The negative crystallization activity energy becomes smaller at the same crystallization conversion rate, and the Hoffman-Lauritzen parameters of Kg, U*, σe and q increase. All the results indicate that poly(4-ethylphenol) antioxidant inhibits the crystallization of PP.
2019, 36(5): 548-553
doi: 10.11944/j.issn.1000-0518.2019.05.180276
Abstract:
The phosphors, Ba5-3x/2B4O11:xEu3+(x = 0.02~0.22), were synthesized by high-temperature solid-state reaction method. The luminescence property of Ba5-3x/2B4O11:xEu3+ was studied in this paper. The phase and surface topographies of as-prepared samples were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM). This phosphor can be effectively excited at 393 nm and the emission peaks are located at 596 nm, 621 nm, 657 nm and 706 nm corresponding to the 5D0-7FJ(J = 1, 2, 3, 4) transition of Eu3+ ions, respectively. Therein the 5D0-7F2 electric dipole transition of Eu3+ ions, which locates at 621 nm, is the strongest wave crest. Investigation of Eu3+ content-dependent emission spectra indicates that x = 0.16 is the optimum doping content of Eu3+ ions in the Ba5B4O11 host.
The phosphors, Ba5-3x/2B4O11:xEu3+(x = 0.02~0.22), were synthesized by high-temperature solid-state reaction method. The luminescence property of Ba5-3x/2B4O11:xEu3+ was studied in this paper. The phase and surface topographies of as-prepared samples were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM). This phosphor can be effectively excited at 393 nm and the emission peaks are located at 596 nm, 621 nm, 657 nm and 706 nm corresponding to the 5D0-7FJ(J = 1, 2, 3, 4) transition of Eu3+ ions, respectively. Therein the 5D0-7F2 electric dipole transition of Eu3+ ions, which locates at 621 nm, is the strongest wave crest. Investigation of Eu3+ content-dependent emission spectra indicates that x = 0.16 is the optimum doping content of Eu3+ ions in the Ba5B4O11 host.
2019, 36(5): 554-563
doi: 10.11944/j.issn.1000-0518.2019.05.180231
Abstract:
The dissolution of calix[4]quinone(C4Q) in electrolytes can be inhibited by the C4Q/CMK-3(mesoporous carbon) nanocomposites prepared through perfusion method, but the electrochemical performance of the nanocomposites needs to be further improved. We prepared a serious of C4Q/CMK-3/SWCNTs(single-walled carbon nanotubes) composites with different ratio by deaerating-stirring method. In these composites, SWCNTs substituted conductive carbon blacks Super-P of the original C4Q/CMK-3 composites, which also reduced the content of CMK-3. SEM and electrochemical tests are conducted to investigate the relation of the morphology and electrochemical performance that cased by SWCNTs. The results show that the optimum mass ratio was m(C4Q):m(CMK-3):m(SWCNTs)=(1:1:1), which shows a capacity retention of 55% after 100 cycles at 0.1 C. Even at 1 C, the discharge capacity is still 260 mA·h/g. The significant improvement in the electrochemical performance could be ascribed to the formation of three-dimensional conductive network by SWCNTs.
The dissolution of calix[4]quinone(C4Q) in electrolytes can be inhibited by the C4Q/CMK-3(mesoporous carbon) nanocomposites prepared through perfusion method, but the electrochemical performance of the nanocomposites needs to be further improved. We prepared a serious of C4Q/CMK-3/SWCNTs(single-walled carbon nanotubes) composites with different ratio by deaerating-stirring method. In these composites, SWCNTs substituted conductive carbon blacks Super-P of the original C4Q/CMK-3 composites, which also reduced the content of CMK-3. SEM and electrochemical tests are conducted to investigate the relation of the morphology and electrochemical performance that cased by SWCNTs. The results show that the optimum mass ratio was m(C4Q):m(CMK-3):m(SWCNTs)=(1:1:1), which shows a capacity retention of 55% after 100 cycles at 0.1 C. Even at 1 C, the discharge capacity is still 260 mA·h/g. The significant improvement in the electrochemical performance could be ascribed to the formation of three-dimensional conductive network by SWCNTs.
2019, 36(5): 564-570
doi: 10.11944/j.issn.1000-0518.2019.05.180351
Abstract:
Graphene oxide was synthesized by chemical redox method. The graphene oxide nanoparticles were prepared by ultrasonic fragmentation and peeling, and functionalized by polyethylene glycol(PEG). The modified graphene oxide was loaded with cisplatin. The graphene nano-drug delivery system was characterized by scanning electron microscopy(SEM), ultraviolet-visible absorption spectroscopy(UV-Vis) and Fourier transform infrared spectroscopy(FTIR). The killing effect of graphene nano-drug delivery system on oral squamous cell carcinoma human oral squamous cell carcinoma(KB) cells was examined by cell survival rate experiment(MTT) method. The results demonstrate that the loading rate of graphene nano-drug-loading system is 42.4%. Polyethylene glycol modified nano graphene oxide can reduce the cytotoxicity of nano graphene oxide and improve its biocompatibility. It has dual killing effect on KB cells, which provides a theoretical basis for the clinical application of nano graphene oxide in cancer treatment.
Graphene oxide was synthesized by chemical redox method. The graphene oxide nanoparticles were prepared by ultrasonic fragmentation and peeling, and functionalized by polyethylene glycol(PEG). The modified graphene oxide was loaded with cisplatin. The graphene nano-drug delivery system was characterized by scanning electron microscopy(SEM), ultraviolet-visible absorption spectroscopy(UV-Vis) and Fourier transform infrared spectroscopy(FTIR). The killing effect of graphene nano-drug delivery system on oral squamous cell carcinoma human oral squamous cell carcinoma(KB) cells was examined by cell survival rate experiment(MTT) method. The results demonstrate that the loading rate of graphene nano-drug-loading system is 42.4%. Polyethylene glycol modified nano graphene oxide can reduce the cytotoxicity of nano graphene oxide and improve its biocompatibility. It has dual killing effect on KB cells, which provides a theoretical basis for the clinical application of nano graphene oxide in cancer treatment.
2019, 36(5): 571-577
doi: 10.11944/j.issn.1000-0518.2019.05.180266
Abstract:
Electrocatalytic hydrogen evolution reaction(HER) provides one of the most important pathways for the crisis of energy consumption. The research of both highly efficient as well as highly stable non-noble metal electrocatalysts is the key point of commercial application of HER. In this paper, through direct pyrolysis of bimetallic ZnCo zeolitic imidazolate frameworks(ZIFs), the electrocatalyst of evenly distributed Co nanoparticle coated by nitrogen-doped graphitic carbon(V-Co@NC, V, vacancy) could be easily prepared. The existence of Zn element in the precursor could prevent efficiently the aggregation of Co nanoparticles, and help for the formation of uniformly distributed Co nanoparticles. Such unique nanostructure prevents direct contact between cobalt and electrolyte, promots their durability. Meanwhile, the existence of nitrogen dopants enhances the conductivity of catalyst, and contributes to the HER activity greatly. As a result, as-prepared V-Co@NC catalyst exhibits high electrocatalytic activity towards HER in both acidic and alkaline electrolyte, meanwhile the activity remains stable even after 5000 cycles. These performances indicate promising commercial application of the V-Co@NC catalyst. This work opens a new way for the development of HER electrocatalysts with both high activity and stability.
Electrocatalytic hydrogen evolution reaction(HER) provides one of the most important pathways for the crisis of energy consumption. The research of both highly efficient as well as highly stable non-noble metal electrocatalysts is the key point of commercial application of HER. In this paper, through direct pyrolysis of bimetallic ZnCo zeolitic imidazolate frameworks(ZIFs), the electrocatalyst of evenly distributed Co nanoparticle coated by nitrogen-doped graphitic carbon(V-Co@NC, V, vacancy) could be easily prepared. The existence of Zn element in the precursor could prevent efficiently the aggregation of Co nanoparticles, and help for the formation of uniformly distributed Co nanoparticles. Such unique nanostructure prevents direct contact between cobalt and electrolyte, promots their durability. Meanwhile, the existence of nitrogen dopants enhances the conductivity of catalyst, and contributes to the HER activity greatly. As a result, as-prepared V-Co@NC catalyst exhibits high electrocatalytic activity towards HER in both acidic and alkaline electrolyte, meanwhile the activity remains stable even after 5000 cycles. These performances indicate promising commercial application of the V-Co@NC catalyst. This work opens a new way for the development of HER electrocatalysts with both high activity and stability.
Influence of Pinecone-Like Ferric Oxide on the Electro-Optical Properties of Nematic Liquid Crystals
2019, 36(5): 578-584
doi: 10.11944/j.issn.1000-0518.2019.05.180297
Abstract:
Liquid crystal(LC) materials are widely used in LC displays(LCD). However, due to the presence of impurities in liquid crystal, the application voltage of liquid crystal becomes large, which results in the increase of energy consumption. In order to decrease the threshold voltage and saturation voltage, nanoparticles are usually added to LC to improve the electro-optical performance. In this paper, pinecone-like ferric oxide(P-Fe2O3) nanoparticles with uniform shape and size were prepared by a simple chemical precipitation method. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl(5CB) is doped with pinecone-like Fe2O3 nanoparticles in different doping contents. The results show that the best electro-optical properties of the LC is achieved when the doping mass fraction is 0.5%. The threshold voltage and saturation voltage decrease by 24.8% and 45.2%, respectively, the contrast ratio increases by 46%, and the response time decreases to 17.6 ms. The property is superior to the ordinary Fe2O3 nanoparticles doped in 5CB with the threshold voltage and saturation voltage decreased by 15% and 16% under the same condition, which is attributed to the uniform dispersion of pinecone-like Fe2O3 in nematic LC 5CB and the adsorption of impurity ions by the rough surface of pinecone-like Fe2O3 abating the shielding effect.
Liquid crystal(LC) materials are widely used in LC displays(LCD). However, due to the presence of impurities in liquid crystal, the application voltage of liquid crystal becomes large, which results in the increase of energy consumption. In order to decrease the threshold voltage and saturation voltage, nanoparticles are usually added to LC to improve the electro-optical performance. In this paper, pinecone-like ferric oxide(P-Fe2O3) nanoparticles with uniform shape and size were prepared by a simple chemical precipitation method. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl(5CB) is doped with pinecone-like Fe2O3 nanoparticles in different doping contents. The results show that the best electro-optical properties of the LC is achieved when the doping mass fraction is 0.5%. The threshold voltage and saturation voltage decrease by 24.8% and 45.2%, respectively, the contrast ratio increases by 46%, and the response time decreases to 17.6 ms. The property is superior to the ordinary Fe2O3 nanoparticles doped in 5CB with the threshold voltage and saturation voltage decreased by 15% and 16% under the same condition, which is attributed to the uniform dispersion of pinecone-like Fe2O3 in nematic LC 5CB and the adsorption of impurity ions by the rough surface of pinecone-like Fe2O3 abating the shielding effect.
2019, 36(5): 585-594
doi: 10.11944/j.issn.1000-0518.2019.05.180258
Abstract:
Sensitive detection of metal-containing proteins is extremely important in pathology. Superoxide dismutase(SOD) was represented as metal-containing protein to prepare protein imprinted polymers(PIPs) and used for electrochemical biosensor. SOD was used as a template molecule and as a catalyst for electrochemically mediated atom transfer radical polymerization(eATRP) reaction to prepare SOD PIPs. This method does not require transition metal ions and owns the advantages of simple preparation, reagent saving, environmental protection, etc. In this experiment, we selected L-cysteine(L-cys) and nano gold modified gold electrode(Au/L-cys/nanoAu) as one working electrode for catalytic reduction of SOD, and initiator (4-mercaptophenyl 2-bromo-2-methylpropanoate, 4-HTP-Br) modified Au electrode as another working electrode for SOD PIPs modification. The electrode modified with PIPs was characterized by cyclic voltammetry(CV) and X ray photoelectron spectroscopy(XPS). Finally, the PIPs-modified electrode was used as a biosensor for the determination of SOD by differential pulse voltammetry(DPV) measurement. The linear range is 1.0×10-7 to 100 mg/L with the detection limit of 6.8×10-8 mg/L(S/N=3), the correlation coefficient is 0.995. Compared with other methods for detecting SOD, this method has a wider linear range and lower detection limits. This work is significant for the preparation of PIPs, eATRP catalyzed by proteins and the sensitive detection of metal-containing proteins.
Sensitive detection of metal-containing proteins is extremely important in pathology. Superoxide dismutase(SOD) was represented as metal-containing protein to prepare protein imprinted polymers(PIPs) and used for electrochemical biosensor. SOD was used as a template molecule and as a catalyst for electrochemically mediated atom transfer radical polymerization(eATRP) reaction to prepare SOD PIPs. This method does not require transition metal ions and owns the advantages of simple preparation, reagent saving, environmental protection, etc. In this experiment, we selected L-cysteine(L-cys) and nano gold modified gold electrode(Au/L-cys/nanoAu) as one working electrode for catalytic reduction of SOD, and initiator (4-mercaptophenyl 2-bromo-2-methylpropanoate, 4-HTP-Br) modified Au electrode as another working electrode for SOD PIPs modification. The electrode modified with PIPs was characterized by cyclic voltammetry(CV) and X ray photoelectron spectroscopy(XPS). Finally, the PIPs-modified electrode was used as a biosensor for the determination of SOD by differential pulse voltammetry(DPV) measurement. The linear range is 1.0×10-7 to 100 mg/L with the detection limit of 6.8×10-8 mg/L(S/N=3), the correlation coefficient is 0.995. Compared with other methods for detecting SOD, this method has a wider linear range and lower detection limits. This work is significant for the preparation of PIPs, eATRP catalyzed by proteins and the sensitive detection of metal-containing proteins.
2019, 36(5): 595-602
doi: 10.11944/j.issn.1000-0518.2019.05.180310
Abstract:
A new type of "Off-On" electrochemiluminescence(ECL) biosensor using Ru(bpy)32+/β-CD-AuNPs/Nafion complex and ferrocene-labeled DNA(Fc-DNA) was designed to detect mercury ions in Chinese medicinal materials Danshen. The ECL biosensor includes an ECL substrate and an ECL signal switch. Ru(bpy)32+/β-CD-AuNPs/Nafion complex modified glassy carbon electrode was used as the ECL substrate, which could bring about a clear and stable ECL signal by Ru(bpy)32+, and hairpin-like Fc-DNA probe acted as the ECL signal switch, which was designed by molecular recognition strategy and attached to β-CD-AuNPs through host-guest interaction between β-CD and ferrocene. Compared with previous methods of mercury ion detection, this method has the advantages of convenient operation, high sensitivity, good repeatability and low detection limit. The ECL biosensor offered good linear responses for Hg2+ in the range of 0.04~800 ng/mL with a detection limit of 0.02 ng/mL(S/N=3).
A new type of "Off-On" electrochemiluminescence(ECL) biosensor using Ru(bpy)32+/β-CD-AuNPs/Nafion complex and ferrocene-labeled DNA(Fc-DNA) was designed to detect mercury ions in Chinese medicinal materials Danshen. The ECL biosensor includes an ECL substrate and an ECL signal switch. Ru(bpy)32+/β-CD-AuNPs/Nafion complex modified glassy carbon electrode was used as the ECL substrate, which could bring about a clear and stable ECL signal by Ru(bpy)32+, and hairpin-like Fc-DNA probe acted as the ECL signal switch, which was designed by molecular recognition strategy and attached to β-CD-AuNPs through host-guest interaction between β-CD and ferrocene. Compared with previous methods of mercury ion detection, this method has the advantages of convenient operation, high sensitivity, good repeatability and low detection limit. The ECL biosensor offered good linear responses for Hg2+ in the range of 0.04~800 ng/mL with a detection limit of 0.02 ng/mL(S/N=3).
2019, 36(5): 603-610
doi: 10.11944/j.issn.1000-0518.2019.05.180259
Abstract:
The new photoluminescent carbon dots were prepared via high temperature pyrolysis of Chinese herbal medicine Chuan Bergamot. The average particle size of photoluminescent carbon dots is 6 nm, the maximum excitation wavelength is 285 nm, and the maximum photoluminescent emission wavelength is 340 nm. Based on the good photoluminescent properties of carbon dots and the quenching effect of Hg2+ on photoluminescence of carbon dots, a new method for the detection of Hg2+ was established. The experimental results show that the method has good selectivity and anti-interference ability with a response time of 2 min in 0.2 mol/L phosphate buffer solution(pH=7.0). The linear range of Hg2+ concentration is from 0.2 μmol/L to 40 μmol/L, the correlation coefficient is 0.9996, and the detection limit is 0.052 μmol/L. When 2.0 μmol/L and 40.0 μmol/L Hg2+ are added to the actual water sample, the relative standard deviation(RSD) and the recovery ranges are from 0.3% to 2.4% and from 99.5% to 101.1%, respectively. Therefore, it can be applied in the analysis and detection of Hg2+ in real samples.
The new photoluminescent carbon dots were prepared via high temperature pyrolysis of Chinese herbal medicine Chuan Bergamot. The average particle size of photoluminescent carbon dots is 6 nm, the maximum excitation wavelength is 285 nm, and the maximum photoluminescent emission wavelength is 340 nm. Based on the good photoluminescent properties of carbon dots and the quenching effect of Hg2+ on photoluminescence of carbon dots, a new method for the detection of Hg2+ was established. The experimental results show that the method has good selectivity and anti-interference ability with a response time of 2 min in 0.2 mol/L phosphate buffer solution(pH=7.0). The linear range of Hg2+ concentration is from 0.2 μmol/L to 40 μmol/L, the correlation coefficient is 0.9996, and the detection limit is 0.052 μmol/L. When 2.0 μmol/L and 40.0 μmol/L Hg2+ are added to the actual water sample, the relative standard deviation(RSD) and the recovery ranges are from 0.3% to 2.4% and from 99.5% to 101.1%, respectively. Therefore, it can be applied in the analysis and detection of Hg2+ in real samples.
