Nowadays, at a time of growing concern for sustainable development and compliance with environmental standards and legislation, the detection of heavy metal contaminants in environmental matrices represents a difficul...Nowadays, at a time of growing concern for sustainable development and compliance with environmental standards and legislation, the detection of heavy metal contaminants in environmental matrices represents a difficult but important task. The current major limitation lies in the poor detection limits of the targeted pollutant＇s trace concentrations by the available conventional techniques. In order to elaborate a novel ＂living＂ self assembled electrochemical 3-D biosensor, the authors propose a new concept to overcome this shortcoming. The advantages of the properties of polyelectrolyte-functionalized NBs （nanobeads） are combined along with the use of non covalently strongly bound micro-organisms. The designed 3-D biosensor is all the more promising as it has showed a significantly improved sensitivity. In fact, the detection limits of the tested heavy metals （cadmium and mercury） were as low as 1.0 × 10^-12 mol.L-1 and six to seven orders of magnitude lower than those provided by conventional 2-D biosensors. Furthermore, it is potentially applicable to a wide range of bioreceptor-pollutant detection systems.展开更多
A novel Opto-Chemical Ring Resonator （OCRR） has been presented for detecting gas odorant. The sensor is designed based on Morphology Dependent Resonances （MDR） which follows Maxwell＇s electromagnetic equations. I...A novel Opto-Chemical Ring Resonator （OCRR） has been presented for detecting gas odorant. The sensor is designed based on Morphology Dependent Resonances （MDR） which follows Maxwell＇s electromagnetic equations. In this paper, we have presented a novel technique to integrate chemical science and optical technology by using OCRR. Optical resonances of electromagnetic wave propagations in dielectric micro-ring resonator have been developed based on asymptotic approach. Parametric studies based on developed asymptotic expression have been presented to determine the resonance frequency at particular chemical composition. Finite element simulation is used to predict the performance of the sensor and found encouraging results for odorant sensing. Parametric studies show that present study will help to develop novel OCRR sensors tbr micro/nano technology and biomedical applications.展开更多
Because of their easy tunability in structure,porosity,and micro-environment,metal-organic frameworks(MOFs)have recently attracted numerous attentions in various fields.The detection of ascorbic acid(AA),dopamine(DA),...Because of their easy tunability in structure,porosity,and micro-environment,metal-organic frameworks(MOFs)have recently attracted numerous attentions in various fields.The detection of ascorbic acid(AA),dopamine(DA),and uric acid(UA)is of great significance not only in biomedicine and neurochemistry but also in disease diagnosis and pathology research.Herein,a series of bimetallic-organic frameworks,MIL-125(Ti-Fe)-x%NH_(2)(x=0,25,50,75,and 100),was successfully synthesized.MIL-125(Ti-Fe)-x%NH_(2)family was employed as electrochemical sensors for the detection of AA,DA,and UA,and MIL-125(Ti-Fe)-100%NH_(2)exhibited the most promising performance with 50%carbon black doping in 0.1 mol·L^(-1)PBS(pH=7.10).In addition,the as-prepared MIL-125(Ti-Fe)-100%NH_(2)/GCE exhibited excellent anti-interference performance and good stability,which provided a promising platform for future utilization in real sample analysis.展开更多
The paper reports a novel amperometric biosensor for catechol based on immobilization of a highly sensitive horseradish peroxidase by affinity interactions on metal chelate-functionalized agarose/carbon nanotubes comp...The paper reports a novel amperometric biosensor for catechol based on immobilization of a highly sensitive horseradish peroxidase by affinity interactions on metal chelate-functionalized agarose/carbon nanotubes composites. Metal chelate affinity takes advantage of the affinity of Ni2＋ ions to bind strongly and reversibly to histidine or cysteine tails found on the surface of the horseradish peroxidase. Thus, enzymes with such residues in their molecules can be easily attached to functionalized aga- rose/carbon nanotubes composites support containing a nickel chelate. Linear sweep voltammograms and amperometry are used to study the proposed electrochemical biosensor. Catechol is determined by direct reduction of biocatalytically liberated quinone species at -0.05 V （vs. SCE）. The effect ofpH, applied electrode potential and the concentration of H2O2 on the sensitivity of the biosensor has been investigated. The performance of the proposed biosensor is tested using four different phenolic compounds, showing very high sensitivity, in particular, the linearity of cateehol is observed from 2.0 × 10-8 to 1.05×10-5 M with a detection limit of 5.0×10-9 M.展开更多
Hydrothermal carbon （HTC） is typically well- dispersed, but it remains a great challenge for HTC to become conductive. Co-doping with heteroatoms has been confirmed to be an effective strategy to significantly promo...Hydrothermal carbon （HTC） is typically well- dispersed, but it remains a great challenge for HTC to become conductive. Co-doping with heteroatoms has been confirmed to be an effective strategy to significantly promote the electrical conductivity of carbon. Moreover, there is no simple and green method to construct sensitive HTC based electro- chemical biosensors until now. In this paper, N and S dual-doped carbon （NS-C） with ultra-low charge transfer resistance is easily synthesized from L-cysteine and glucose in a hydrothermal reaction system. The morphology, structural prop- erties and electrochemical properties of the as-prepared NS-C are analyzed. In comparison with the undoped hydrothermal （UC） modified glassy carbon electrode （GCE）, the charge transfer resistance of UC （476 Ω） is ten times the value of NS- C （46 Ω）. The developed biosensor shows a better performance to detect glucose in a wide concentration range （50-2500 μmol L^-1） with the detection limit of 1.77 μmol L^-1 （S/N-3） and a high sensitivity （0.0554 μA cm^-2μmol^-1 L）. The apparent Michaelis-Menten constant value of GCE/NS-C/GOx/nafion modified electrode is 0.769 mmol L^-1, indicating a high affinity of glucose oxidase to glucose. These results demonstrate that the hydrothermal method is an effective way for prepar- ing high electrical conductivity carbon with excellent performances in biosensor application.展开更多
文摘Nowadays, at a time of growing concern for sustainable development and compliance with environmental standards and legislation, the detection of heavy metal contaminants in environmental matrices represents a difficult but important task. The current major limitation lies in the poor detection limits of the targeted pollutant＇s trace concentrations by the available conventional techniques. In order to elaborate a novel ＂living＂ self assembled electrochemical 3-D biosensor, the authors propose a new concept to overcome this shortcoming. The advantages of the properties of polyelectrolyte-functionalized NBs （nanobeads） are combined along with the use of non covalently strongly bound micro-organisms. The designed 3-D biosensor is all the more promising as it has showed a significantly improved sensitivity. In fact, the detection limits of the tested heavy metals （cadmium and mercury） were as low as 1.0 × 10^-12 mol.L-1 and six to seven orders of magnitude lower than those provided by conventional 2-D biosensors. Furthermore, it is potentially applicable to a wide range of bioreceptor-pollutant detection systems.
文摘A novel Opto-Chemical Ring Resonator （OCRR） has been presented for detecting gas odorant. The sensor is designed based on Morphology Dependent Resonances （MDR） which follows Maxwell＇s electromagnetic equations. In this paper, we have presented a novel technique to integrate chemical science and optical technology by using OCRR. Optical resonances of electromagnetic wave propagations in dielectric micro-ring resonator have been developed based on asymptotic approach. Parametric studies based on developed asymptotic expression have been presented to determine the resonance frequency at particular chemical composition. Finite element simulation is used to predict the performance of the sensor and found encouraging results for odorant sensing. Parametric studies show that present study will help to develop novel OCRR sensors tbr micro/nano technology and biomedical applications.
基金the Natural Science Foundation of Science and Technology Department of Jilin Province(grant No.20210101131JC)the Fundamental Research Funds for the Central Universities(grant No.2412020FZ009 and 2412022ZD048)
文摘Because of their easy tunability in structure,porosity,and micro-environment,metal-organic frameworks(MOFs)have recently attracted numerous attentions in various fields.The detection of ascorbic acid(AA),dopamine(DA),and uric acid(UA)is of great significance not only in biomedicine and neurochemistry but also in disease diagnosis and pathology research.Herein,a series of bimetallic-organic frameworks,MIL-125(Ti-Fe)-x%NH_(2)(x=0,25,50,75,and 100),was successfully synthesized.MIL-125(Ti-Fe)-x%NH_(2)family was employed as electrochemical sensors for the detection of AA,DA,and UA,and MIL-125(Ti-Fe)-100%NH_(2)exhibited the most promising performance with 50%carbon black doping in 0.1 mol·L^(-1)PBS(pH=7.10).In addition,the as-prepared MIL-125(Ti-Fe)-100%NH_(2)/GCE exhibited excellent anti-interference performance and good stability,which provided a promising platform for future utilization in real sample analysis.
基金supported by the National Outstanding Youth Foundations of China (50725825)National Basic Research Program of China (2007CB310501 & 2011CB935704)+2 种基金National Natural Science Foundation of China (50908113)the Natural Science Foundation of Jiangxi Province (2008GZH0008)the Youth Foundation of Jiangxi Provincial Department of Education (GJJ09483)
文摘The paper reports a novel amperometric biosensor for catechol based on immobilization of a highly sensitive horseradish peroxidase by affinity interactions on metal chelate-functionalized agarose/carbon nanotubes composites. Metal chelate affinity takes advantage of the affinity of Ni2＋ ions to bind strongly and reversibly to histidine or cysteine tails found on the surface of the horseradish peroxidase. Thus, enzymes with such residues in their molecules can be easily attached to functionalized aga- rose/carbon nanotubes composites support containing a nickel chelate. Linear sweep voltammograms and amperometry are used to study the proposed electrochemical biosensor. Catechol is determined by direct reduction of biocatalytically liberated quinone species at -0.05 V （vs. SCE）. The effect ofpH, applied electrode potential and the concentration of H2O2 on the sensitivity of the biosensor has been investigated. The performance of the proposed biosensor is tested using four different phenolic compounds, showing very high sensitivity, in particular, the linearity of cateehol is observed from 2.0 × 10-8 to 1.05×10-5 M with a detection limit of 5.0×10-9 M.
基金supported by the National Basic Research Program of China (973 Program,2014CB931900)UCAS Young Teacher Research Fund (Y55103NY00,Y55103EY00,and Y25102TN00)+1 种基金Beijing Natural Science Foundation (Z160002)The Chinese Academy of Sciences Key Project Foundation (KFZD-SW-202)
文摘Hydrothermal carbon （HTC） is typically well- dispersed, but it remains a great challenge for HTC to become conductive. Co-doping with heteroatoms has been confirmed to be an effective strategy to significantly promote the electrical conductivity of carbon. Moreover, there is no simple and green method to construct sensitive HTC based electro- chemical biosensors until now. In this paper, N and S dual-doped carbon （NS-C） with ultra-low charge transfer resistance is easily synthesized from L-cysteine and glucose in a hydrothermal reaction system. The morphology, structural prop- erties and electrochemical properties of the as-prepared NS-C are analyzed. In comparison with the undoped hydrothermal （UC） modified glassy carbon electrode （GCE）, the charge transfer resistance of UC （476 Ω） is ten times the value of NS- C （46 Ω）. The developed biosensor shows a better performance to detect glucose in a wide concentration range （50-2500 μmol L^-1） with the detection limit of 1.77 μmol L^-1 （S/N-3） and a high sensitivity （0.0554 μA cm^-2μmol^-1 L）. The apparent Michaelis-Menten constant value of GCE/NS-C/GOx/nafion modified electrode is 0.769 mmol L^-1, indicating a high affinity of glucose oxidase to glucose. These results demonstrate that the hydrothermal method is an effective way for prepar- ing high electrical conductivity carbon with excellent performances in biosensor application.
