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2022 Volume 50 Issue 4
2022, 50(4): 495-505
doi: 10.19756/j.issn.0253-3820.210843
Abstract:
Graphene quantum dots(GQDs), as a kind of zero-dimensional carbon nano material, not only have excellent properties of graphene, but also have quantum confinement effect and boundary effect. GQDs with different nano-size can be obtained by various preparation methods. The surface of GQDs has abundant functional groups, which can be further functionalized by compounding with other materials to meet the detection requirements of different gases and broaden its application range in gas sensing. In this review, the preparation methods of GQDs and their applications in gas sensing are introduced. In addition, the application prospect and development direction of GQDs in gas sensing are also prospected.
Graphene quantum dots(GQDs), as a kind of zero-dimensional carbon nano material, not only have excellent properties of graphene, but also have quantum confinement effect and boundary effect. GQDs with different nano-size can be obtained by various preparation methods. The surface of GQDs has abundant functional groups, which can be further functionalized by compounding with other materials to meet the detection requirements of different gases and broaden its application range in gas sensing. In this review, the preparation methods of GQDs and their applications in gas sensing are introduced. In addition, the application prospect and development direction of GQDs in gas sensing are also prospected.
2022, 50(4): 506-515
doi: 10.19756/j.issn.0253-3820.221017
Abstract:
In recent years, microneedles have been widely used in the fields of medical biological diagnosis, such as sampling and detection, transdermal drug delivery, etc, because of its painless and convenient advantages. Microfluidic chip is used to control micro-fluid, which has the advantages such as less reagent loss, fast detection speed and sensitive detection, etc. It is also popular in biochemical analysis, environmental science and other fields. The development of microfluidic chips and microneedles in the early stage is relatively independent. With the wide application of microfluidic chips and microneedles in biomedicine and other fields and the emergence of advanced micromachining methods such as 3D printing, in recent years, microneedles and microfluidic chips show a trend of combined application. For example, micro-fluidic channels are added on the surface or inside of the micro-needle to realize accurate sampling or drug delivery, or micro-needles are embedded inside the micro-fluidic chip to realize accurate control of droplet generation. Although the combination of microneedles and microfluidic chips can be widely used in subcutaneous sampling, drug transportation, medical diagnosis and other fields, it is still unclear how to realize the integrated preparation and application of microneedles and microfluidic chips. In this paper, the combined application of microneedles and microfluidic chips at home and abroad in recent years is reviewed, the method system of the combined application of microfluidic chips and microneedles is summarized, and the development trend of the combined application of microneedles and microfluidic chips in the future is prospected.
In recent years, microneedles have been widely used in the fields of medical biological diagnosis, such as sampling and detection, transdermal drug delivery, etc, because of its painless and convenient advantages. Microfluidic chip is used to control micro-fluid, which has the advantages such as less reagent loss, fast detection speed and sensitive detection, etc. It is also popular in biochemical analysis, environmental science and other fields. The development of microfluidic chips and microneedles in the early stage is relatively independent. With the wide application of microfluidic chips and microneedles in biomedicine and other fields and the emergence of advanced micromachining methods such as 3D printing, in recent years, microneedles and microfluidic chips show a trend of combined application. For example, micro-fluidic channels are added on the surface or inside of the micro-needle to realize accurate sampling or drug delivery, or micro-needles are embedded inside the micro-fluidic chip to realize accurate control of droplet generation. Although the combination of microneedles and microfluidic chips can be widely used in subcutaneous sampling, drug transportation, medical diagnosis and other fields, it is still unclear how to realize the integrated preparation and application of microneedles and microfluidic chips. In this paper, the combined application of microneedles and microfluidic chips at home and abroad in recent years is reviewed, the method system of the combined application of microfluidic chips and microneedles is summarized, and the development trend of the combined application of microneedles and microfluidic chips in the future is prospected.
2022, 50(4): 516-524
doi: 10.19756/j.issn.0253-3820.221101
Abstract:
Extracellular adenosine triphosphate(ATP) as a signaling molecule participates in a series of physiological processes, and its abnormal metabolism is closely related to many diseases(e.g., inflammation, infectious diseases). Developing methods for in situ detection of extracellular ATP is of great importance to elucidating the mechanism of relevant diseases and their diagnosis. This work reports DNA molecular machine-integrated microneedle patches. The developed microneedle patch allows for rapidly swelling in aqueous solution and in-situ sampling of target ATP molecules; the DNA molecular machine driven by ATP can realize fluorescence signal amplification. Benefiting from these traits, the microneedle patch-based analytical system shows excellent performance for ATP detection, including wide detection range(1-500 μmol/L), low limit of detection(1 μmol/L) and good selectivity.The result demonstrated that this microneedle patch-based analytical system enables in situ monitoring of ATP secreted by living cells under the stimulation of 0.1 mol/L K+, and the ATP concentration is determined to be(10.9 ± 1.6) μmol/L, consistent with previous work. This work provides a promising analytical platform for in situ monitoring of extracellular ATP.
Extracellular adenosine triphosphate(ATP) as a signaling molecule participates in a series of physiological processes, and its abnormal metabolism is closely related to many diseases(e.g., inflammation, infectious diseases). Developing methods for in situ detection of extracellular ATP is of great importance to elucidating the mechanism of relevant diseases and their diagnosis. This work reports DNA molecular machine-integrated microneedle patches. The developed microneedle patch allows for rapidly swelling in aqueous solution and in-situ sampling of target ATP molecules; the DNA molecular machine driven by ATP can realize fluorescence signal amplification. Benefiting from these traits, the microneedle patch-based analytical system shows excellent performance for ATP detection, including wide detection range(1-500 μmol/L), low limit of detection(1 μmol/L) and good selectivity.The result demonstrated that this microneedle patch-based analytical system enables in situ monitoring of ATP secreted by living cells under the stimulation of 0.1 mol/L K+, and the ATP concentration is determined to be(10.9 ± 1.6) μmol/L, consistent with previous work. This work provides a promising analytical platform for in situ monitoring of extracellular ATP.
2022, 50(4): 525-534
doi: 10.19756/j.issn.0253-3820.201787
Abstract:
A sensitive and convenient sensor for detection of Pb2+ was established based on the specific recognition of Pb2+ and substrate DNA(sDNA), coupling with Fe3O4 nano-magnetic beads(MB) as sensor platform, portable glucose meter(PGM) as signal capture terminal and DNA walking device as signal amplification strategy. The nanogold-functionalized Poly(amidoamine() Au/PAMAM) dendrimers prepared by reduction method were modified by glucose oxidase(GOx) and sDNA to form sDNA/GOx/Au/PAMAM complex. Based on the complementary base pairing principle, the sDNA/GOx/Au/PAMAM complex was captured on the MB modified by capture DNA(c DNA), and the DNA enzymes(DNAzyme) could bind to the un-paired parts of sDNA. In the presence of target, Pb2+ could specifically recognize cleavage sites on sDNA and shear it, meanwhile released DNAzyme and GOx/Au/PAMAM. The former continued to bind with the next sDNA, and then the new identification-split-release circulation was opened.The circulation could be called DNA walker device, and the release quantity of GOx/Au/PAMAM was increased to realize signal amplification. The supernatant(GOx/Au/PAMAM), separated by magnetic separation, could oxidize glucose(Glu) in the reaction solution, and the change value of Glu concentration was monitored with PGM, thus indirectly detecting the target Pb2+ concentration. Under the optimal conditions, the PGM response of the system showed a good linear relationship with the logarithm of Pb2+ concentration ranging from 1.00 pmol/L to 1.00 μmol/L, and the detection limit was 0.66 pmol/L.
A sensitive and convenient sensor for detection of Pb2+ was established based on the specific recognition of Pb2+ and substrate DNA(sDNA), coupling with Fe3O4 nano-magnetic beads(MB) as sensor platform, portable glucose meter(PGM) as signal capture terminal and DNA walking device as signal amplification strategy. The nanogold-functionalized Poly(amidoamine() Au/PAMAM) dendrimers prepared by reduction method were modified by glucose oxidase(GOx) and sDNA to form sDNA/GOx/Au/PAMAM complex. Based on the complementary base pairing principle, the sDNA/GOx/Au/PAMAM complex was captured on the MB modified by capture DNA(c DNA), and the DNA enzymes(DNAzyme) could bind to the un-paired parts of sDNA. In the presence of target, Pb2+ could specifically recognize cleavage sites on sDNA and shear it, meanwhile released DNAzyme and GOx/Au/PAMAM. The former continued to bind with the next sDNA, and then the new identification-split-release circulation was opened.The circulation could be called DNA walker device, and the release quantity of GOx/Au/PAMAM was increased to realize signal amplification. The supernatant(GOx/Au/PAMAM), separated by magnetic separation, could oxidize glucose(Glu) in the reaction solution, and the change value of Glu concentration was monitored with PGM, thus indirectly detecting the target Pb2+ concentration. Under the optimal conditions, the PGM response of the system showed a good linear relationship with the logarithm of Pb2+ concentration ranging from 1.00 pmol/L to 1.00 μmol/L, and the detection limit was 0.66 pmol/L.
2022, 50(4): 535-544
doi: 10.19756/j.issn.0253-3820.221067
Abstract:
A method for synthesis of an amphiphilic aerogel with remarkable peroxidase-like activity was developed by using poly(vinyl alcohol) (PVA) as skeleton and maleic acid(MA) as auxiliary crosslinker.Large amount of carboxyl and ester groups could be exposed on aerogel surface by tuning the dosage of MA, which acted as the active sites and binding sites for the substrate material. A colorimetric method for glucose sensing by the catalyzed chromogenic reaction between 3, 3', 5, 5'-tetramethylbenzidine and H2O2, was thus established. The linear detection range of glucose in buffer system was 17.4-80.0 μmol/L, with limit of detection(3σ) of 17.4 μmol/L. While in diluted human serum, the linear detection range was 27.4 μmol/L-1.0 mmol/L, with limit of detection(3σ) of 27.4 μmol/L. This method was used in detection of glucose in human serum, with recoveries of 96.8%-103.0% and relative standard deviations of 0.8%-3.9%, and the detection results were highly consistent with those obtained from the commercial glucose meter. This study innovatively developed a three-dimensional macroscope organic aerogel as a new type of artificial enzyme, broadening the design philosophy and enriching the synthesis strategy. It was promising in construction of portable sensors by virtue of the lightness in weight and eligible mechanical properties.
A method for synthesis of an amphiphilic aerogel with remarkable peroxidase-like activity was developed by using poly(vinyl alcohol) (PVA) as skeleton and maleic acid(MA) as auxiliary crosslinker.Large amount of carboxyl and ester groups could be exposed on aerogel surface by tuning the dosage of MA, which acted as the active sites and binding sites for the substrate material. A colorimetric method for glucose sensing by the catalyzed chromogenic reaction between 3, 3', 5, 5'-tetramethylbenzidine and H2O2, was thus established. The linear detection range of glucose in buffer system was 17.4-80.0 μmol/L, with limit of detection(3σ) of 17.4 μmol/L. While in diluted human serum, the linear detection range was 27.4 μmol/L-1.0 mmol/L, with limit of detection(3σ) of 27.4 μmol/L. This method was used in detection of glucose in human serum, with recoveries of 96.8%-103.0% and relative standard deviations of 0.8%-3.9%, and the detection results were highly consistent with those obtained from the commercial glucose meter. This study innovatively developed a three-dimensional macroscope organic aerogel as a new type of artificial enzyme, broadening the design philosophy and enriching the synthesis strategy. It was promising in construction of portable sensors by virtue of the lightness in weight and eligible mechanical properties.
2022, 50(4): 545-553
doi: 10.19756/j.issn.0253-3820.221035
Abstract:
The MoS2-modified straw carbon dots nanozyme(Mo, S-CDs) was prepared by hydrothermal synthesis for detection of content of uric acid in human urine. This work fully exploited the inherent advantages of straw structure and realized the recycling of biomass waste. The characterization of Mo, S-CDs showed that Mo and S elements were successfully modified into the structure of straw carbon dots, and the Mo, S-CDs were spherical with abundant functional groups on the surface to ensure their good dispersion in aqueous medium and amorphous carbon structure at crystal level. The Mo, S-CDs had the activity of mimetic peroxidase and showed high catalytic efficiency. They were able to rapidly catalyze the oxidation of 3, 3', 5, 5'-tetramethylbenzidine in a system containing H2O2 to generate chromogenic product, which visually showed a characteristic blue color signal in response and reached a peak absorbance at 652 nm.The cascade catalytic sensing system of uric acid-Mo, S-CDs was constructed based on the sensing ability of Mo, S-CDs for H2O2 generation catalyzed by uric acid, which was applied to the detection of uric acid in human urine. The sensing system had good linear range(5-100 μmol/L), low detection limit(1.8 μmol/L), satisfied recovery(96.8%-106.1%) and good relative standard deviation(less than 5%) in detection of uric acid. The results showed that Mo, S-CDs had advantages over natural peroxidases in terms of wide applicable temperature range and high stability, which would make them more widely useful in fields such as life analysis.
The MoS2-modified straw carbon dots nanozyme(Mo, S-CDs) was prepared by hydrothermal synthesis for detection of content of uric acid in human urine. This work fully exploited the inherent advantages of straw structure and realized the recycling of biomass waste. The characterization of Mo, S-CDs showed that Mo and S elements were successfully modified into the structure of straw carbon dots, and the Mo, S-CDs were spherical with abundant functional groups on the surface to ensure their good dispersion in aqueous medium and amorphous carbon structure at crystal level. The Mo, S-CDs had the activity of mimetic peroxidase and showed high catalytic efficiency. They were able to rapidly catalyze the oxidation of 3, 3', 5, 5'-tetramethylbenzidine in a system containing H2O2 to generate chromogenic product, which visually showed a characteristic blue color signal in response and reached a peak absorbance at 652 nm.The cascade catalytic sensing system of uric acid-Mo, S-CDs was constructed based on the sensing ability of Mo, S-CDs for H2O2 generation catalyzed by uric acid, which was applied to the detection of uric acid in human urine. The sensing system had good linear range(5-100 μmol/L), low detection limit(1.8 μmol/L), satisfied recovery(96.8%-106.1%) and good relative standard deviation(less than 5%) in detection of uric acid. The results showed that Mo, S-CDs had advantages over natural peroxidases in terms of wide applicable temperature range and high stability, which would make them more widely useful in fields such as life analysis.
2022, 50(4): 554-563
doi: 10.19756/j.issn.0253-3820.210892
Abstract:
Mesoporous chabazite-non-woven was prepared by in situ growth method using non-woven as the substrate, and then silver nanoparticles-mesoporous chabazite-non-woven(AgNPs-mCHA-NW) composite material was obtained after AgNPs were anchored. The structure and morphology of the as-prepared materials were characterized by X-ray diffraction(XRD), field-emission scanning electron microscope(FE-SEM), X-ray photoelectron spectroscopy(XPS), automatic physical adsorption instrument(BET), and thermogravimetric analysis(TGA). The anticoagulant rabbit blood was used to evaluate the hemostatic result of the as-prepared materials in vitro. The antibacterial properties of the materials against Escherichia coli(E. coli) and Staphylococcus aureus(S. aureus) were studied by inhibition zone method. Finally, the mouse tail vein incision model was established to investigate the hemostatic effect of the material in vivo. The experiment results showed that the clotting time in vitro and hemostatic time in vivo of AgNPs-mCHA-NW were lower than that of commercial hemostatic gauze, which indicated that AgNPs-mCHA-NW had good hemostatic effect. The results of the inhibition zone experiment proved that the antibacterial performance of AgNPs-mCHA-NW was significantly better than the commercial silver nanoparticles wound bandage(AgNPs-WB). AgNPs-mCHA-NW combined mesoporous chabazite with AgNPs, which not only achieved rapid and effective hemostasis of wounds, but also showed great antibacterial property, thus providing a new platform for emergency treatment and rapid recovery of massive bleeding wounds.
Mesoporous chabazite-non-woven was prepared by in situ growth method using non-woven as the substrate, and then silver nanoparticles-mesoporous chabazite-non-woven(AgNPs-mCHA-NW) composite material was obtained after AgNPs were anchored. The structure and morphology of the as-prepared materials were characterized by X-ray diffraction(XRD), field-emission scanning electron microscope(FE-SEM), X-ray photoelectron spectroscopy(XPS), automatic physical adsorption instrument(BET), and thermogravimetric analysis(TGA). The anticoagulant rabbit blood was used to evaluate the hemostatic result of the as-prepared materials in vitro. The antibacterial properties of the materials against Escherichia coli(E. coli) and Staphylococcus aureus(S. aureus) were studied by inhibition zone method. Finally, the mouse tail vein incision model was established to investigate the hemostatic effect of the material in vivo. The experiment results showed that the clotting time in vitro and hemostatic time in vivo of AgNPs-mCHA-NW were lower than that of commercial hemostatic gauze, which indicated that AgNPs-mCHA-NW had good hemostatic effect. The results of the inhibition zone experiment proved that the antibacterial performance of AgNPs-mCHA-NW was significantly better than the commercial silver nanoparticles wound bandage(AgNPs-WB). AgNPs-mCHA-NW combined mesoporous chabazite with AgNPs, which not only achieved rapid and effective hemostasis of wounds, but also showed great antibacterial property, thus providing a new platform for emergency treatment and rapid recovery of massive bleeding wounds.
2022, 50(4): 564-573
doi: 10.19756/j.issn.0253-3820.210880
Abstract:
NiO/Zn2SnO4 hierarchical nanoflowers were successfully synthesized by hydrothermal method combined with subsequent solution impregnation process. Gas sensor with a side-heated gas sensor structure was fabricated by utilizing the obtained NiO/Zn2SnO4 as sensing material. Several characterization techniques such as X-ray diffraction(XRD) patterns, scanning electron microscopy(SEM), transmission electron microscope(TEM) and X-ray photoelectron spectroscopy(XPS) were employed to investigate the composition, morphology and microstructure of the samples. The results showed that the Zn2SnO4 synthesized via hydrothermal method took on a hierarchical nanoflower structure composed of nano-lamellae, and NiO was successfully decorated on the surface of the Zn2SnO4 nanoflowers as nanoparticles through solution impregnation. The gas sensing performances of pure Zn2SnO4 and NiO/Zn2SnO4 composites were investigated and the testing results revealed that the NiO/Zn2SnO4 composites exhibited excellent sensing performances to ethanol. The response presented a linear relationship with ethanol concentration in the range of 1-100 μL/L(R2=0.9990), the response to 100 μL/L ethanol reached 46.5 at 230℃, and the response and recovery time was 3 s and 16 s, respectively. Moreover, the NiO/Zn2SnO4-based sensor possessed great selectivity and stability. Compared with pure Zn2SnO4 nanoflowers, the sensing properties of NiO/Zn2SnO4 composites were improved dramatically, and the enhancement may ascribe to the p-n type heterojunctions formed between NiO and Zn2SnO4 as well as the catalysis synergetic effect of NiO. The research on the NiO/Zn2SnO4-based sensor provided a reference for highly sensitive detection of ethanol.
NiO/Zn2SnO4 hierarchical nanoflowers were successfully synthesized by hydrothermal method combined with subsequent solution impregnation process. Gas sensor with a side-heated gas sensor structure was fabricated by utilizing the obtained NiO/Zn2SnO4 as sensing material. Several characterization techniques such as X-ray diffraction(XRD) patterns, scanning electron microscopy(SEM), transmission electron microscope(TEM) and X-ray photoelectron spectroscopy(XPS) were employed to investigate the composition, morphology and microstructure of the samples. The results showed that the Zn2SnO4 synthesized via hydrothermal method took on a hierarchical nanoflower structure composed of nano-lamellae, and NiO was successfully decorated on the surface of the Zn2SnO4 nanoflowers as nanoparticles through solution impregnation. The gas sensing performances of pure Zn2SnO4 and NiO/Zn2SnO4 composites were investigated and the testing results revealed that the NiO/Zn2SnO4 composites exhibited excellent sensing performances to ethanol. The response presented a linear relationship with ethanol concentration in the range of 1-100 μL/L(R2=0.9990), the response to 100 μL/L ethanol reached 46.5 at 230℃, and the response and recovery time was 3 s and 16 s, respectively. Moreover, the NiO/Zn2SnO4-based sensor possessed great selectivity and stability. Compared with pure Zn2SnO4 nanoflowers, the sensing properties of NiO/Zn2SnO4 composites were improved dramatically, and the enhancement may ascribe to the p-n type heterojunctions formed between NiO and Zn2SnO4 as well as the catalysis synergetic effect of NiO. The research on the NiO/Zn2SnO4-based sensor provided a reference for highly sensitive detection of ethanol.
2022, 50(4): 574-584
doi: 10.19756/j.issn.0253-3820.210878
Abstract:
Two fluorescent molecules(1 and 2) were synthesized by salicylaldehyde and 4-(diethylamino) salicylaldehyde with naphthalene isothiocyanate.Their structures were characterized by nuclear magnetic resonance(NMR) and mass spectrometry(MS).The results of UV-vis absorption spectra and fluorescence spectra showed that molecule 1 and molecule 2 had high sensitivity to fluoride ion(F-) in DMSO solution, which could be used as fluorescence probes for F- detection.Probe 1(molecule 1) showed fluorescence enhancement to F-, and the fluorescence intensity increased by 15 times when F-concentration was 20.0μmol/L.Compared to probe 1, probe 2(molecule 2) showed high selectivity ratio fluorescence recognition for F- due to the presence of diethylamino group.The addition of F-could cause decrease of fluorescence emission peak of probe 2 at 456 nm, while a new fluorescence emission peak appeared at 503 nm and gradually increased.Probes 1 and 2 had low detection limits of 0.35μmol/L and 0.68μmol/L toward F-respectively.By the B-H equation, the constants of probe 1 and probe 2 to F- were 3.8×104 L/mol and 6.98×103 L/mol, indicating that the two probes had strong binding affinity with F-.In addition, the binding modes between probe 1 and probe 2 and F-were investigated by 1H NMR.The analysis of experimental results showed that the fluorescence recognition mechanism of both two probes was intramolecular charge transfer(ICT).Finally, the test papers prepared by the two probes were used for simple fluorescence detection of F- in toothpaste solution, which proved their good practicability.
Two fluorescent molecules(1 and 2) were synthesized by salicylaldehyde and 4-(diethylamino) salicylaldehyde with naphthalene isothiocyanate.Their structures were characterized by nuclear magnetic resonance(NMR) and mass spectrometry(MS).The results of UV-vis absorption spectra and fluorescence spectra showed that molecule 1 and molecule 2 had high sensitivity to fluoride ion(F-) in DMSO solution, which could be used as fluorescence probes for F- detection.Probe 1(molecule 1) showed fluorescence enhancement to F-, and the fluorescence intensity increased by 15 times when F-concentration was 20.0μmol/L.Compared to probe 1, probe 2(molecule 2) showed high selectivity ratio fluorescence recognition for F- due to the presence of diethylamino group.The addition of F-could cause decrease of fluorescence emission peak of probe 2 at 456 nm, while a new fluorescence emission peak appeared at 503 nm and gradually increased.Probes 1 and 2 had low detection limits of 0.35μmol/L and 0.68μmol/L toward F-respectively.By the B-H equation, the constants of probe 1 and probe 2 to F- were 3.8×104 L/mol and 6.98×103 L/mol, indicating that the two probes had strong binding affinity with F-.In addition, the binding modes between probe 1 and probe 2 and F-were investigated by 1H NMR.The analysis of experimental results showed that the fluorescence recognition mechanism of both two probes was intramolecular charge transfer(ICT).Finally, the test papers prepared by the two probes were used for simple fluorescence detection of F- in toothpaste solution, which proved their good practicability.
2022, 50(4): 585-592
doi: 10.19756/j.issn.0253-3820.221077
Abstract:
Preconcentration is an effective method to detect trace biochemical substances. In this work, a microfluidic enrichment chip based on ion exchange membrane with trident structure was developed for both the detection of charged particles in water environment and the enrichment of anions based on the principle of ion concentration polarization. The chip was fabricated by 3D printing and micro-nano processing technology. By controlling the potential difference between enrichment zone and buffer zone, the electroosmotic force and repulsion force could be controlled to obtain a stable depletion zone and enrichment zone. In the enrichment experiment, when the negatively charged sodium fluorescein was used as the enrichment object, the factors affecting the enrichment factor such as voltage and enrichment time were explored, and the enrichment effect was verified in the concentration range of 0.2-3.0 μmol/L. The study showed that the trident ion exchange membrane could effectively avoid the permeation of the solution in the enrichment zone and buffer zone as experimental results, which greatly improved the enrichment factor. The enrichment factor of different concentrations of sodium fluorescein on this chip was close, and the highest was 102 times, which meant that the chip had the ability of enriching anions.
Preconcentration is an effective method to detect trace biochemical substances. In this work, a microfluidic enrichment chip based on ion exchange membrane with trident structure was developed for both the detection of charged particles in water environment and the enrichment of anions based on the principle of ion concentration polarization. The chip was fabricated by 3D printing and micro-nano processing technology. By controlling the potential difference between enrichment zone and buffer zone, the electroosmotic force and repulsion force could be controlled to obtain a stable depletion zone and enrichment zone. In the enrichment experiment, when the negatively charged sodium fluorescein was used as the enrichment object, the factors affecting the enrichment factor such as voltage and enrichment time were explored, and the enrichment effect was verified in the concentration range of 0.2-3.0 μmol/L. The study showed that the trident ion exchange membrane could effectively avoid the permeation of the solution in the enrichment zone and buffer zone as experimental results, which greatly improved the enrichment factor. The enrichment factor of different concentrations of sodium fluorescein on this chip was close, and the highest was 102 times, which meant that the chip had the ability of enriching anions.
2022, 50(4): 593-601
doi: 10.19756/j.issn.0253-3820.221092
Abstract:
Reduction of CO2 into useful fuels and chemicals through electrochemical catalytic processes is currently the most promising way to address CO2 emissions and utilize CO2.Herein, we report a method to use atomically well-defined gold nanoclusters Au24 NCs and Au25 NCs as catalytically active sites for electrochemical carbon dioxide electroreduction reaction (CO2RR) by supporting the as-prepared Au24 NCs and Au25 NCs on carbon substrates.The electrochemical results show that Au24 NCs/C achieves the highest CO Faradaic efficiency of 77.5%at-0.58 V, and Au25 NCs/C achieves the highest CO Faradaic efficiency of 68.9% at-0.68 V.By comparison, it can be found that the highest CO Faradaic efficiency obtained on Au24 NCs/C is 8.6% higher than that on Au25 NCs/C.Meanwhile, compared to Au25 NCs/C, the potential for the highest CO Faradaic efficiency has a positive shift of 100 mV on Au24 NCs/C.These data indicate that Au24 NCs/C has better catalytic activity than Au25 NCs/C for CO2RR, which may be attributed to the different coordination structures of the two gold clusters.Compared with Au25 NCs/C, Au24 NCs/C lacks a central atom, and therefore its peripheral ligands may be more easily to drop off from the cluster surface, resulting in more exposed Au active sites for CO2RR.This study reveals the structure effect of metal clusters on their electrocatalytic properties and is helpful for the design of high-performance and highly selective CO2RR catalysts.
Reduction of CO2 into useful fuels and chemicals through electrochemical catalytic processes is currently the most promising way to address CO2 emissions and utilize CO2.Herein, we report a method to use atomically well-defined gold nanoclusters Au24 NCs and Au25 NCs as catalytically active sites for electrochemical carbon dioxide electroreduction reaction (CO2RR) by supporting the as-prepared Au24 NCs and Au25 NCs on carbon substrates.The electrochemical results show that Au24 NCs/C achieves the highest CO Faradaic efficiency of 77.5%at-0.58 V, and Au25 NCs/C achieves the highest CO Faradaic efficiency of 68.9% at-0.68 V.By comparison, it can be found that the highest CO Faradaic efficiency obtained on Au24 NCs/C is 8.6% higher than that on Au25 NCs/C.Meanwhile, compared to Au25 NCs/C, the potential for the highest CO Faradaic efficiency has a positive shift of 100 mV on Au24 NCs/C.These data indicate that Au24 NCs/C has better catalytic activity than Au25 NCs/C for CO2RR, which may be attributed to the different coordination structures of the two gold clusters.Compared with Au25 NCs/C, Au24 NCs/C lacks a central atom, and therefore its peripheral ligands may be more easily to drop off from the cluster surface, resulting in more exposed Au active sites for CO2RR.This study reveals the structure effect of metal clusters on their electrocatalytic properties and is helpful for the design of high-performance and highly selective CO2RR catalysts.
2022, 50(4): 602-612
doi: 10.19756/j.issn.0253-3820.210832
Abstract:
The current clinical castration treatment drugs for prostate cancer are mainly focus on the reduction of systemic androgen or blocking their binding to androgen receptor(AR). However, due to the complexity of signal pathway activation, developing new castration methods to achieve selective removal of androgen from local tissues of prostate cancer is of great significance to enhance the therapeutic effect and reduce systemic side effects. In this work, 3-aminopropyltriethoxysilane(APTES) and octylmethoxysilane(OTMS) were used to modify magnetic nanoparticles to prepare amphiphilic nanoparticles(AO-MNPs). The prepared AO-MNPs enhanced the affinity of carriers towards template testosterone(TSTO), benefiting from the function of the amino and hydrophobic alkyl chain. And then, AO-MNPs was used as the core, TSTO as the template molecule, and dopamine(DA) as the functional monomer to prepared superparamagnetic core-shell testosterone magnetic molecularly imprinted polymers(T/AO-MMIPs) by a two-step template immobilization method. The strategy of two-step immobilization template method not only synergistically enhanced the affinity of the imprinted holes for TSTO, but also made the imprinted holes well arranged in an orderly and regular distribution on the surface of the carrier. Thus, the fabricated T/AO-MMIPs were evaluated to possess high adsorption amount and good selectivity, which played an important role in the selective removal of specific biomolecules from complex biological tissues. When T/AO-MMIPs were taken up by prostate cancer tissue through EPR, they could selectively adsorb the inter TSTO molecules in cells, thereby blocking the combination of TSTO and AR, inhibiting AR activity and exerting prostate cancer tumor growth inhibitory effect, while no obvious effect on normal cells. The as-prepared T/AO-MMIPs nanoplatform provided a new research strategy for enhancing the treatment of prostate cancer castration.
The current clinical castration treatment drugs for prostate cancer are mainly focus on the reduction of systemic androgen or blocking their binding to androgen receptor(AR). However, due to the complexity of signal pathway activation, developing new castration methods to achieve selective removal of androgen from local tissues of prostate cancer is of great significance to enhance the therapeutic effect and reduce systemic side effects. In this work, 3-aminopropyltriethoxysilane(APTES) and octylmethoxysilane(OTMS) were used to modify magnetic nanoparticles to prepare amphiphilic nanoparticles(AO-MNPs). The prepared AO-MNPs enhanced the affinity of carriers towards template testosterone(TSTO), benefiting from the function of the amino and hydrophobic alkyl chain. And then, AO-MNPs was used as the core, TSTO as the template molecule, and dopamine(DA) as the functional monomer to prepared superparamagnetic core-shell testosterone magnetic molecularly imprinted polymers(T/AO-MMIPs) by a two-step template immobilization method. The strategy of two-step immobilization template method not only synergistically enhanced the affinity of the imprinted holes for TSTO, but also made the imprinted holes well arranged in an orderly and regular distribution on the surface of the carrier. Thus, the fabricated T/AO-MMIPs were evaluated to possess high adsorption amount and good selectivity, which played an important role in the selective removal of specific biomolecules from complex biological tissues. When T/AO-MMIPs were taken up by prostate cancer tissue through EPR, they could selectively adsorb the inter TSTO molecules in cells, thereby blocking the combination of TSTO and AR, inhibiting AR activity and exerting prostate cancer tumor growth inhibitory effect, while no obvious effect on normal cells. The as-prepared T/AO-MMIPs nanoplatform provided a new research strategy for enhancing the treatment of prostate cancer castration.
2022, 50(4): 613-622
doi: 10.19756/j.issn.0253-3820.210834
Abstract:
The proteomes of white shrimp(Penaeus vannamei), black tiger shrimp(Penaeus monodon), cod(Dissostichus eleginoides) and Atlantic salmon(Salmo salar)from different geographical origins were investigated using ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry based on relatively quantitative differential proteomics. The quantitative protein data of samples from different geographical origins were mined by chemometric tools to reveal proteomic differences. By screening analysis of parameters such as variable importance in projection, S-plot analysis, knife-cut confidence interval and fold change, 15, 3, 2 and 19 potential protein biomarkers corresponding to Penaeus vannamei, Penaeus monodon, Dissostichus eleginoides and Salmo salar were obtained respectively for identifying the geographical origin of fish and shrimp products. The proposed protocol provided an alternative method for geographical provenance of important aquaculture products in international trade and basic data for supporting official control of geographical origin as well as quality controls of aquaculture products.
The proteomes of white shrimp(Penaeus vannamei), black tiger shrimp(Penaeus monodon), cod(Dissostichus eleginoides) and Atlantic salmon(Salmo salar)from different geographical origins were investigated using ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry based on relatively quantitative differential proteomics. The quantitative protein data of samples from different geographical origins were mined by chemometric tools to reveal proteomic differences. By screening analysis of parameters such as variable importance in projection, S-plot analysis, knife-cut confidence interval and fold change, 15, 3, 2 and 19 potential protein biomarkers corresponding to Penaeus vannamei, Penaeus monodon, Dissostichus eleginoides and Salmo salar were obtained respectively for identifying the geographical origin of fish and shrimp products. The proposed protocol provided an alternative method for geographical provenance of important aquaculture products in international trade and basic data for supporting official control of geographical origin as well as quality controls of aquaculture products.
2022, 50(4): 623-633
doi: 10.19756/j.issn.0253-3820.201269
Abstract:
A ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method was developed for determination of perfluoroalkyl acids and alternatives of perfluorooctane sulfonate(PFOS) in atmospheric fine particles(PM2.5).Half of filter was cut into small pieces and extracted by methanol for 3 times at 40℃.The extraction solutions were combined and the supernatant was purified by ENVI-Carb SPE cartridge.The effluent was dried by nitrogen at 40℃, re-dissolved with 0.2 mL of methanol, and centrifuged, and the supernatants were quantitatively analyzed in multiple reactions monitoring mode by mass spectrometry with electro-spray ionization in negative mode.The method showed a good linearity for detection of 22 compounds, with the correlation coefficients of more than 0.9980, the limits of detection of 0.01-0.52 pg/m3, the limits of quantification of 0.03-1.74 pg/m3, the spiked recoveries of 78.6%-119.3% and the relative standard deviations of 1.7%-10.5%.The PFAAs and alternatives of PFOS in PM2.5 collected in November 2019 in Beijing were determined by the method.Four kinds of PFAAs were detected in 29 samples, including PFOA, PFHp A, PFOS and PFHx A, and the detection rates were 100%, 79.3%, 62.1% and 58.6%, respectively.The concentrations were in the range of 1.94-86.9 pg/m3, 0.31-4.39 pg/m3, 0.29-3.51 pg/m3 and 0.36-1.69 pg/m3, respectively.
A ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method was developed for determination of perfluoroalkyl acids and alternatives of perfluorooctane sulfonate(PFOS) in atmospheric fine particles(PM2.5).Half of filter was cut into small pieces and extracted by methanol for 3 times at 40℃.The extraction solutions were combined and the supernatant was purified by ENVI-Carb SPE cartridge.The effluent was dried by nitrogen at 40℃, re-dissolved with 0.2 mL of methanol, and centrifuged, and the supernatants were quantitatively analyzed in multiple reactions monitoring mode by mass spectrometry with electro-spray ionization in negative mode.The method showed a good linearity for detection of 22 compounds, with the correlation coefficients of more than 0.9980, the limits of detection of 0.01-0.52 pg/m3, the limits of quantification of 0.03-1.74 pg/m3, the spiked recoveries of 78.6%-119.3% and the relative standard deviations of 1.7%-10.5%.The PFAAs and alternatives of PFOS in PM2.5 collected in November 2019 in Beijing were determined by the method.Four kinds of PFAAs were detected in 29 samples, including PFOA, PFHp A, PFOS and PFHx A, and the detection rates were 100%, 79.3%, 62.1% and 58.6%, respectively.The concentrations were in the range of 1.94-86.9 pg/m3, 0.31-4.39 pg/m3, 0.29-3.51 pg/m3 and 0.36-1.69 pg/m3, respectively.
2022, 50(4): 634-642
doi: 10.19756/j.issn.0253-3820.210851
Abstract:
A method for fast quantitative analysis of bongkrekic acid and iso-bongkrekic acid in human plasma and urine by liquid chromatography-tandem mass spectrometry(LC-MS/MS) coupled with isotope dilution was developed. The sample was extracted with acetonitrile, separated on a C18 column(100 mm × 2.1 mm, 1.9 μm), and detected in selected reaction monitoring(SRM) mode via positive electrospray ionization. The internal standard method was used for quantitation with solvent standard curve. Bongkrekic acid and iso-bongkrekic acid showed good linearity in the concentration range of 2.0-400.0 μg/L with correlation coefficients of higher than 0.9984. The quantitation limits of bongkrekic acid and iso-bongkrekic acid in human plasma and urine were 2.0 μg/L. The intra-and inter-day recoveries were 89.7%-109.6% and 86.2%-104.2%, respectively, at spiked concentrations of 2.0 μg/L, 10.0 μg/L, 40.0 μg/L, and 200.0 μg/L. The inter-and intra-day relative standard deviations(RSDs) were lower than 9.8%. The method was accurate, fast and easy to operate, and could satisfy the requirements of public health emergency testing or clinical testing.
A method for fast quantitative analysis of bongkrekic acid and iso-bongkrekic acid in human plasma and urine by liquid chromatography-tandem mass spectrometry(LC-MS/MS) coupled with isotope dilution was developed. The sample was extracted with acetonitrile, separated on a C18 column(100 mm × 2.1 mm, 1.9 μm), and detected in selected reaction monitoring(SRM) mode via positive electrospray ionization. The internal standard method was used for quantitation with solvent standard curve. Bongkrekic acid and iso-bongkrekic acid showed good linearity in the concentration range of 2.0-400.0 μg/L with correlation coefficients of higher than 0.9984. The quantitation limits of bongkrekic acid and iso-bongkrekic acid in human plasma and urine were 2.0 μg/L. The intra-and inter-day recoveries were 89.7%-109.6% and 86.2%-104.2%, respectively, at spiked concentrations of 2.0 μg/L, 10.0 μg/L, 40.0 μg/L, and 200.0 μg/L. The inter-and intra-day relative standard deviations(RSDs) were lower than 9.8%. The method was accurate, fast and easy to operate, and could satisfy the requirements of public health emergency testing or clinical testing.
2022, 50(4): 643-658
doi: 10.19756/j.issn.0253-3820.221003
Abstract:
Flavor compounds of livestock milk mainly include acids, esters, ketones, aldehydes and alkanes, however the composition of flavor compound of each animal milk may related to species, forage, metabolism disorder, as well other complicated factors. In this study, a total of 53 raw milk samples of Mongolia horse, Bactrian camel, Holstein cow, Saanen goat, Maiwa yak and Murrah buffalo were collected. Flavor compounds of raw milk were determined and identified by proton transfer reaction-time of flight-mass spectrometry(PTR-TOF-MS), and multivariate statistical analysis was conducted to observe the natural clustering characteristics of six kinds of livestock milk by their flavor compounds. SIMCA and PCA-Class discrimination model were constructed to evaluate the feasibility of authentication on species, geographical origin/local varieties of raw milk by their flavor compounds. As results, there were 27, 23, 16, 21, 21 and 18 kinds of flavor compounds identified in the raw milk of Mongolia horse, Bactrian camel, Holstein cow, Saanen goat, Maiwa yak and Murrah buffalo, respectively, mainly were ketones, acids, aldehydes, alcohols and sulfur compounds. Multivariate statistical analysis showed that six kinds of livestock raw milk were clustered into six groups and the clustering distance consistent with taxonomy of these species. Mongolia horse and Bactrian camel milk clusters were both separated by geographical origins. Alxa camels and Xinjiang camel milk clusters from same origin were separated but did not influence original separation. Six species of raw milk of livestock were identified, and the accuracy of external verification of SIMCA and PCA-class model were 92.72% and 98.38% respectively. The external verification accuracy of Mongolian horse milk and Bactrian camel milk from different geographical regions and local varieties were above 83.00%. The results showed that the authentication of species, geographical origin/local varieties of animal milk by flavor compounds or MS fingerprint modeling was promising. The study introduced another innovative strategy and methodology to authentication of species, geographical origin/local varieties of animal milk.
Flavor compounds of livestock milk mainly include acids, esters, ketones, aldehydes and alkanes, however the composition of flavor compound of each animal milk may related to species, forage, metabolism disorder, as well other complicated factors. In this study, a total of 53 raw milk samples of Mongolia horse, Bactrian camel, Holstein cow, Saanen goat, Maiwa yak and Murrah buffalo were collected. Flavor compounds of raw milk were determined and identified by proton transfer reaction-time of flight-mass spectrometry(PTR-TOF-MS), and multivariate statistical analysis was conducted to observe the natural clustering characteristics of six kinds of livestock milk by their flavor compounds. SIMCA and PCA-Class discrimination model were constructed to evaluate the feasibility of authentication on species, geographical origin/local varieties of raw milk by their flavor compounds. As results, there were 27, 23, 16, 21, 21 and 18 kinds of flavor compounds identified in the raw milk of Mongolia horse, Bactrian camel, Holstein cow, Saanen goat, Maiwa yak and Murrah buffalo, respectively, mainly were ketones, acids, aldehydes, alcohols and sulfur compounds. Multivariate statistical analysis showed that six kinds of livestock raw milk were clustered into six groups and the clustering distance consistent with taxonomy of these species. Mongolia horse and Bactrian camel milk clusters were both separated by geographical origins. Alxa camels and Xinjiang camel milk clusters from same origin were separated but did not influence original separation. Six species of raw milk of livestock were identified, and the accuracy of external verification of SIMCA and PCA-class model were 92.72% and 98.38% respectively. The external verification accuracy of Mongolian horse milk and Bactrian camel milk from different geographical regions and local varieties were above 83.00%. The results showed that the authentication of species, geographical origin/local varieties of animal milk by flavor compounds or MS fingerprint modeling was promising. The study introduced another innovative strategy and methodology to authentication of species, geographical origin/local varieties of animal milk.
