Diabetes mellitus represents a major global health issue,driving the need for noninvasive alternatives to traditional blood glucose monitoring methods.Recent advancements in wearable technology have introduced skin-in...Diabetes mellitus represents a major global health issue,driving the need for noninvasive alternatives to traditional blood glucose monitoring methods.Recent advancements in wearable technology have introduced skin-interfaced biosensors capable of analyzing sweat and skin biomarkers,providing innovative solutions for diabetes diagnosis and monitoring.This review comprehensively discusses the current developments in noninvasive wearable biosensors,emphasizing simultaneous detection of biochemical biomarkers(such as glucose,cortisol,lactate,branched-chain amino acids,and cytokines)and physiological signals(including heart rate,blood pressure,and sweat rate)for accurate,personalized diabetes management.We explore innovations in multimodal sensor design,materials science,biorecognition elements,and integration techniques,highlighting the importance of advanced data analytics,artificial intelligence-driven predictive algorithms,and closed-loop therapeutic systems.Additionally,the review addresses ongoing challenges in biomarker validation,sensor stability,user compliance,data privacy,and regulatory considerations.A holistic,multimodal approach enabled by these next-generation wearable biosensors holds significant potential for improving patient outcomes and facilitating proactive healthcare interventions in diabetes management.展开更多
The development of low-cost,non-enzymatic glucose biosensors is crucial for advancing accessible diabetes management.This paper presents the experimental testing of an extended-gate field-effect transistor(EG-FET)that...The development of low-cost,non-enzymatic glucose biosensors is crucial for advancing accessible diabetes management.This paper presents the experimental testing of an extended-gate field-effect transistor(EG-FET)that uses a gold film as the sensing structure.The system innovatively employs a custom-designed inverting operational amplifier circuit for precise signal acquisition and an Arduino Nano platform for real-time data processing and visualization,eliminating the need for expensive laboratory equipment.At the core of the design is a depletion-mode MOSFET,whose current-voltage properties were characterized.The function of the sensor was demonstrated by testing its response to phosphate-buffered saline containing glucose at different concentrations.A clear modulation of the drain current in the linear region of the EG-FET was observed,and a preliminary analysis revealed a linear correlation between the output current and glucose concentration,indicating the system’s potential for quantitative detection.This study successfully validates the feasibility of a compact,cost-effective,and non-enzymatic EG-FET biosensing platform,establishing a solid foundation for future development of point-of-care diagnostic devices.展开更多
Genetically encoded biosensors are powerful tools for monitoring plant proteins,which could offer high spatial and temporal resolution and help reveal the molecular mechanisms underlying plant growth and stress respon...Genetically encoded biosensors are powerful tools for monitoring plant proteins,which could offer high spatial and temporal resolution and help reveal the molecular mechanisms underlying plant growth and stress responses.However,a comprehensive review focused on the spatiotemporal monitoring of plant proteins using these biosensors is still lacking.This review highlights key advancements in the field,evaluates the strengths and limitations of current biosensors,and discusses their applications for tracking plant protein dynamics.We aim to provide a thorough understanding of genetically encoded biosensors for plant proteins,promote the development of these technologies,and foster deeper insights into molecular mechanisms in plant cells.Future research should prioritize overcoming challenges such as interference from plant autofluorescence and enhancing the sensitivity of biosensors,particularly in complex cellular compartments like chloroplasts and cell walls,to further improve spatial and temporal resolution.展开更多
There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of...There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of simultaneously measuring liquid refractive index under proposed temperature.A fabricated gold grating is placed on one side of a thin gold film for refractive index measurement,while the other with polydimethylsiloxane(PDMS)is deposited on the other side for temperature measurement.We use finite element analysis to research its sensing characteristics.Due to the high refractive index sensitivity of SPR sensors and thermo-optic coefficient of PDMS,we discovered the maximum spectral sensitivity of the sensor is 564 nm/RIU and-50 pm/℃when the liquid refractive index ranges from 1.30 to 1.40 with temperature ranging from 0℃ to 100℃.Numerical results indicate that there may not be mutual interference between two channels for measuring refractive index and temperature,which reduces the complexity of sensor measurements.展开更多
Detecting multiple analytes simultaneously,crucial in disease diagnosis and treatment prognosis,remains challenging.While planar sensing platforms demonstrate this capability,optical fiber sensors still lag behind.An ...Detecting multiple analytes simultaneously,crucial in disease diagnosis and treatment prognosis,remains challenging.While planar sensing platforms demonstrate this capability,optical fiber sensors still lag behind.An operando dual lossy mode resonance(LMR)biosensor fabricated on a D-shaped single-mode fiber(SMF)is proposed for quantification of clinical indicators of inflammatory process,like in COVID-19 infection.Dual LMRs,created via two-step deposition process,yield a nanostructure with distinct SnO_(2) thicknesses on the flat surface of the fiber.Theoretical and experimental analyses confirm its feasibility,showing a sensitivity around 4500 nm/RIU for both LMRs.A novel insight in spatially-separated biofunctionalization of the sensitive fiber regions is validated through fluorescence assays,showcasing selectivity for different immunoglobulins.Real-time and label-free detection of two inflammatory markers,C-reactive protein and Ddimer,empowers the platform capability with a minimum detectable concentration below 1μg/mL for both biomolecules,which is of clinical interest.This proof-of-concept work provides an important leap in fiber-based biosensing for effective and reliable multi-analyte detection,presenting a novel,compact and multi-functional analytical tool.展开更多
The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulti...The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulting selenium nanoparticles were used as a new carrier for horseradish peroxidase to construct H2O2 biosensors with good performances.展开更多
A Pt-nanooarticle/carbon nanotube modified graphite electrode immobilized with cholesterol oxidase/sol＇-gel layer was developed for monitoring cholesterol.Using this electrode,cholesterol concentration（4.0×10^-...A Pt-nanooarticle/carbon nanotube modified graphite electrode immobilized with cholesterol oxidase/sol＇-gel layer was developed for monitoring cholesterol.Using this electrode,cholesterol concentration（4.0×10^-6 tp 1.0×10^-4mol/L）could be determined accurately in the presence of ascorbic or uric acid,and the response time was rapid （〈 20 s）. This biosensor has high sensitivity and selectivity.展开更多
The aim was to experimentally evaluate the antioxidant capacity of different types of bread and of the relative flour used for bread production utilizing a superoxide dismutase （SOD） biosensor recently developed by ...The aim was to experimentally evaluate the antioxidant capacity of different types of bread and of the relative flour used for bread production utilizing a superoxide dismutase （SOD） biosensor recently developed by the present authors. Measurements were carried out by comparing the biosensor response to the concentration of superoxide radical produced in solution using a xanthine/xanthine oxidase system in the presence and in the absence of the antioxidant sample considered, respectively. Precision of antioxidant capacity measures for crust and crumb of the different breads was found to be good （RS D% ≤ 8%） and acceptable for the watery suspension and filtrate of the different flours studied （RSD% ≤ 12%）. The obtained results indicated that general flours show higher antioxidant capacity values than the corresponding breads and that crusts show always an antioxidant capacity definitely larger than the crumb. Lastly, the antioxidant capacity values were compared with those of almond, red pepper and strawberry, three foods containing powerful natural antioxidants.展开更多
A new approach for assembling amperometric mushroom pulp tissue based membrane electrode for determination of L tyrosine analysis is proposed. Ferrocene is used as a mediator of electron transfer between tyrosinase ...A new approach for assembling amperometric mushroom pulp tissue based membrane electrode for determination of L tyrosine analysis is proposed. Ferrocene is used as a mediator of electron transfer between tyrosinase in mushroom tissue and a graphite electrode. The optimal operation conditions are studied. The linear response range of the biosensor is 2 0×10 -4 to 4 5×10 -3 mol·L -1 with response time of less than 5 min and lifetime of at least 30 d. The biosensor can be applied to practical sample analysis.展开更多
Because of the practical advantages such as operation simplicity, low expense of fabrication and suitability for real-time detection, etc., protein-based voltammetric biosensors
A novel reagentless biosensor constructed by the organic dye nile blue (NB) and horseradish peroxidase (HRP) has been fabricated via layer-by-layer (LBL) self-assembly technique. NB premixed with polyanion poly (sodiu...A novel reagentless biosensor constructed by the organic dye nile blue (NB) and horseradish peroxidase (HRP) has been fabricated via layer-by-layer (LBL) self-assembly technique. NB premixed with polyanion poly (sodium-p-styrenesulfonate) (PSS) acts as the mediator between the immobilized HRP and the electrode surface. The response of the biosensor to hydrogen peroxide has been investigated. The linear range of the biosensor to hydrogen peroxide was from 0.20 mmol/L to 7.03 mmol /L with a sensitivity of 8.45 μA/(mmol/L).展开更多
The biocompatiable and low-toxic poly（thiophene-3-aeetic acid） （PTAA） matrix was successfully electrosynthesized in ionic liquid 1-butyl-3-metbylimidazolium hexafluorophosphate （BmimPF6） in comparison with the e...The biocompatiable and low-toxic poly（thiophene-3-aeetic acid） （PTAA） matrix was successfully electrosynthesized in ionic liquid 1-butyl-3-metbylimidazolium hexafluorophosphate （BmimPF6） in comparison with the electrosynthesis of PTAA matrix in acetonitrile （ACN）. Ascorbate oxidase （AO） was used as a model for the development and application of biosensor. Vitamin C （VC） biosensors were facilely fabricated by the covalent immobilization of AO molecules on PTAA matrices electrosynthesized in ACN containing tetrabutylammonium tetrafluoroborate and BmimPF6, respectively. Electrochemical impedance spectroscopy, scanning electron microscopy and FTIR spectroscopy indicated that AO molecules were covalently immobilized on PTAA matrices. Parameters of the as-obtained biosensors such as working potential, pH and temperature have been optimized. The amperometric biosensor based on PTAA matrix electrosynthesized in BmimPF6 exhibited wider linear range, lower detection limit, higher sensitivity and bioaffinity, and better operational and storage stability than that electrosynthesized in ACN under optimal conditions. The as-obtained biosensor based on PTAA matrix electrosynthesized in BmimPF6 was employed for the detection of VC content in comme：rcial juices, and the result was close to the data given by manufacturers. Excellent results indicate that the PTAA matrix electrosynthesized in ionic liquid is a promising platform for the covalent immobilization of biologically-active species and the development of biosensors.展开更多
Pyruvate, a final metabolite of glycogen, is widely distributed over many kinds of tissue fluids of human bodys. The determination for its contents is of clinical importance in gynaecology. Titrimetry, colorimetry and...Pyruvate, a final metabolite of glycogen, is widely distributed over many kinds of tissue fluids of human bodys. The determination for its contents is of clinical importance in gynaecology. Titrimetry, colorimetry and chromatography are common used methods. In recent years, enzymatic mthod has proved to be one of the most important determination techniques for its simplicity and fastness. However, in some cases, the use of purified enzymes as biocatalysts yields systems with a short useful lifetime owing, to enzyme instability A tiss展开更多
Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor sho...Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18 靘ol/L glucose with detection limit of 0.5 靘ol/L glucose.展开更多
A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by...A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by electrochemical and spectroscopic techniques. Results showed that the immobilized HRP exhibited direct electrochemical behavior toward the reduction of H2O2. The resulting biosensor shows a fast amperometric response (<2 s) to H2O2. The linear response range was from 5.0×10-7～1.0×10-5 mol/L with a detection limit of 1.0×10-7mol/L. Moreover, the biosensor has a good reproducibility, and long-term stability.展开更多
Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor wa...Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spreeta biosensor kits were used to detect Salmonella Typhimurium on chicken carcass successfully. A taste sensor like electronic tongue or biosensors was used to basically ＂taste＂ the object and differentiated one object from the other with different taste sensor signatures. The surface plasmon resonance biosensor has potential for use in rapid, real-time detection and identification of bacteria, and to study the interaction of organisms with dif- ferent antisera or other molecular species. The selectivity of the SPR biosensor was assayed using a series of antibody con- centrations and dilution series of the organism. The SPR biosensor showed promising to detect the existence of Salmonella Typhimurium at 1 x 106 CFU/ml. Initial results show that the SPR biosensor has the potential for its application in pathogenic bacteria monitoring. However, more tests need to be done to confirm the detection limitation.展开更多
A new strategy using an arnperometric biosensor with Escherichia coli （E. coli） that provides a rapid toxicity determination of chemical compounds is described. The CellSense biosensor system comprises a biological ...A new strategy using an arnperometric biosensor with Escherichia coli （E. coli） that provides a rapid toxicity determination of chemical compounds is described. The CellSense biosensor system comprises a biological component immobilized in intimate contact with a transducer which converts the biochemical signal into a quantifiable electrical signal. Toxicity assessment of heavy metals using E.coli biosensors could be finished within 30 min and the 50% effective concentrations （ECso） values of four heavy metals were determined. The results shows that inhibitory effects of four heavy metals to E.coli can be ranked in a decreasing order of Hg^2＋ 〉 Cu^2＋ 〉 Zn^2＋ 〉 Ni^2＋, which accords to the results of conventional bacterial counting method. The toxicity test of organic compounds by using CellSense biosensor was also demonstrated. The CellSense biosensor with E. coli shows a good, reproducible behavior and can be used for reproducible measurements.展开更多
文摘Diabetes mellitus represents a major global health issue,driving the need for noninvasive alternatives to traditional blood glucose monitoring methods.Recent advancements in wearable technology have introduced skin-interfaced biosensors capable of analyzing sweat and skin biomarkers,providing innovative solutions for diabetes diagnosis and monitoring.This review comprehensively discusses the current developments in noninvasive wearable biosensors,emphasizing simultaneous detection of biochemical biomarkers(such as glucose,cortisol,lactate,branched-chain amino acids,and cytokines)and physiological signals(including heart rate,blood pressure,and sweat rate)for accurate,personalized diabetes management.We explore innovations in multimodal sensor design,materials science,biorecognition elements,and integration techniques,highlighting the importance of advanced data analytics,artificial intelligence-driven predictive algorithms,and closed-loop therapeutic systems.Additionally,the review addresses ongoing challenges in biomarker validation,sensor stability,user compliance,data privacy,and regulatory considerations.A holistic,multimodal approach enabled by these next-generation wearable biosensors holds significant potential for improving patient outcomes and facilitating proactive healthcare interventions in diabetes management.
文摘The development of low-cost,non-enzymatic glucose biosensors is crucial for advancing accessible diabetes management.This paper presents the experimental testing of an extended-gate field-effect transistor(EG-FET)that uses a gold film as the sensing structure.The system innovatively employs a custom-designed inverting operational amplifier circuit for precise signal acquisition and an Arduino Nano platform for real-time data processing and visualization,eliminating the need for expensive laboratory equipment.At the core of the design is a depletion-mode MOSFET,whose current-voltage properties were characterized.The function of the sensor was demonstrated by testing its response to phosphate-buffered saline containing glucose at different concentrations.A clear modulation of the drain current in the linear region of the EG-FET was observed,and a preliminary analysis revealed a linear correlation between the output current and glucose concentration,indicating the system’s potential for quantitative detection.This study successfully validates the feasibility of a compact,cost-effective,and non-enzymatic EG-FET biosensing platform,establishing a solid foundation for future development of point-of-care diagnostic devices.
基金the National Key Research and Development Program of China(2021YFD1700102)the National Science Fund for Distinguished Young Scholars(22422702)+1 种基金Knowledge Innovation Program of Wuhan-Basic Research(No.2022013301015174)Prof.Alexander Jones at Cambridge University for his guidance and contribution.
文摘Genetically encoded biosensors are powerful tools for monitoring plant proteins,which could offer high spatial and temporal resolution and help reveal the molecular mechanisms underlying plant growth and stress responses.However,a comprehensive review focused on the spatiotemporal monitoring of plant proteins using these biosensors is still lacking.This review highlights key advancements in the field,evaluates the strengths and limitations of current biosensors,and discusses their applications for tracking plant protein dynamics.We aim to provide a thorough understanding of genetically encoded biosensors for plant proteins,promote the development of these technologies,and foster deeper insights into molecular mechanisms in plant cells.Future research should prioritize overcoming challenges such as interference from plant autofluorescence and enhancing the sensitivity of biosensors,particularly in complex cellular compartments like chloroplasts and cell walls,to further improve spatial and temporal resolution.
基金supported by the National Natural Science Foundation of China(No.52276094)the Education Project of Hunan Provincial Department(Nos.20B602 and 22C0112)+2 种基金the Industry University Education Cooperation Project(No.230803117185211)the Research Project on Teaching Reform in Ordinary Undergraduate Universities in Hunan Province(No.202401000142)the Natural Science Foundation of Hunan Province(No.2020JJ4935)。
文摘There is limited amount of research on surface plasmon resonance(SPR)sensors with self-referencing capabilities which are based on dielectric gratings.In the short-wavelength range,a metal grating sensor is capable of simultaneously measuring liquid refractive index under proposed temperature.A fabricated gold grating is placed on one side of a thin gold film for refractive index measurement,while the other with polydimethylsiloxane(PDMS)is deposited on the other side for temperature measurement.We use finite element analysis to research its sensing characteristics.Due to the high refractive index sensitivity of SPR sensors and thermo-optic coefficient of PDMS,we discovered the maximum spectral sensitivity of the sensor is 564 nm/RIU and-50 pm/℃when the liquid refractive index ranges from 1.30 to 1.40 with temperature ranging from 0℃ to 100℃.Numerical results indicate that there may not be mutual interference between two channels for measuring refractive index and temperature,which reduces the complexity of sensor measurements.
基金financial support from the Spanish Agencia Estatal de Investigación (AEI) through project PID2023-149895OB-I00a predoctoral research grant from the Public University of Navarrafinancial support under the National Recovery and Resilience Plan (NRRP),Mission 4,Component 2,Investment 1.1,Call for tender No.1409 published on 14.9.2022 by the Italian Ministry of University and Research (MUR),funded by the European Union–NextGenerationEU–Project Title‘‘Fiber optics sensors as a platform for cancer diagnosis and in vitro model testing”–CUP B53D23024170001-Grant Assignment Decree No.1383 adopted on 01/09/2023 by the Italian MUR.
文摘Detecting multiple analytes simultaneously,crucial in disease diagnosis and treatment prognosis,remains challenging.While planar sensing platforms demonstrate this capability,optical fiber sensors still lag behind.An operando dual lossy mode resonance(LMR)biosensor fabricated on a D-shaped single-mode fiber(SMF)is proposed for quantification of clinical indicators of inflammatory process,like in COVID-19 infection.Dual LMRs,created via two-step deposition process,yield a nanostructure with distinct SnO_(2) thicknesses on the flat surface of the fiber.Theoretical and experimental analyses confirm its feasibility,showing a sensitivity around 4500 nm/RIU for both LMRs.A novel insight in spatially-separated biofunctionalization of the sensitive fiber regions is validated through fluorescence assays,showcasing selectivity for different immunoglobulins.Real-time and label-free detection of two inflammatory markers,C-reactive protein and Ddimer,empowers the platform capability with a minimum detectable concentration below 1μg/mL for both biomolecules,which is of clinical interest.This proof-of-concept work provides an important leap in fiber-based biosensing for effective and reliable multi-analyte detection,presenting a novel,compact and multi-functional analytical tool.
文摘The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulting selenium nanoparticles were used as a new carrier for horseradish peroxidase to construct H2O2 biosensors with good performances.
基金The project is supported by the National Natural Science Foundation of China(29975024,202750-34)Key Project of Science and Technology of Zhejiang Province(2003C21024).The authors acknowledge the Instrumental Analysis Center of Zhejiang University for special measurements.
文摘A Pt-nanooarticle/carbon nanotube modified graphite electrode immobilized with cholesterol oxidase/sol＇-gel layer was developed for monitoring cholesterol.Using this electrode,cholesterol concentration（4.0×10^-6 tp 1.0×10^-4mol/L）could be determined accurately in the presence of ascorbic or uric acid,and the response time was rapid （〈 20 s）. This biosensor has high sensitivity and selectivity.
文摘The aim was to experimentally evaluate the antioxidant capacity of different types of bread and of the relative flour used for bread production utilizing a superoxide dismutase （SOD） biosensor recently developed by the present authors. Measurements were carried out by comparing the biosensor response to the concentration of superoxide radical produced in solution using a xanthine/xanthine oxidase system in the presence and in the absence of the antioxidant sample considered, respectively. Precision of antioxidant capacity measures for crust and crumb of the different breads was found to be good （RS D% ≤ 8%） and acceptable for the watery suspension and filtrate of the different flours studied （RSD% ≤ 12%）. The obtained results indicated that general flours show higher antioxidant capacity values than the corresponding breads and that crusts show always an antioxidant capacity definitely larger than the crumb. Lastly, the antioxidant capacity values were compared with those of almond, red pepper and strawberry, three foods containing powerful natural antioxidants.
文摘A new approach for assembling amperometric mushroom pulp tissue based membrane electrode for determination of L tyrosine analysis is proposed. Ferrocene is used as a mediator of electron transfer between tyrosinase in mushroom tissue and a graphite electrode. The optimal operation conditions are studied. The linear response range of the biosensor is 2 0×10 -4 to 4 5×10 -3 mol·L -1 with response time of less than 5 min and lifetime of at least 30 d. The biosensor can be applied to practical sample analysis.
文摘Because of the practical advantages such as operation simplicity, low expense of fabrication and suitability for real-time detection, etc., protein-based voltammetric biosensors
文摘A novel reagentless biosensor constructed by the organic dye nile blue (NB) and horseradish peroxidase (HRP) has been fabricated via layer-by-layer (LBL) self-assembly technique. NB premixed with polyanion poly (sodium-p-styrenesulfonate) (PSS) acts as the mediator between the immobilized HRP and the electrode surface. The response of the biosensor to hydrogen peroxide has been investigated. The linear range of the biosensor to hydrogen peroxide was from 0.20 mmol/L to 7.03 mmol /L with a sensitivity of 8.45 μA/(mmol/L).
基金financially supported by the NSFC(Nos.50963002,51073074)Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period(Nos.2006BAD02A04,2006BAD01A01)Jiangxi Provincial Department of Science and Technology(2006BAD01A01-2-5)
文摘The biocompatiable and low-toxic poly（thiophene-3-aeetic acid） （PTAA） matrix was successfully electrosynthesized in ionic liquid 1-butyl-3-metbylimidazolium hexafluorophosphate （BmimPF6） in comparison with the electrosynthesis of PTAA matrix in acetonitrile （ACN）. Ascorbate oxidase （AO） was used as a model for the development and application of biosensor. Vitamin C （VC） biosensors were facilely fabricated by the covalent immobilization of AO molecules on PTAA matrices electrosynthesized in ACN containing tetrabutylammonium tetrafluoroborate and BmimPF6, respectively. Electrochemical impedance spectroscopy, scanning electron microscopy and FTIR spectroscopy indicated that AO molecules were covalently immobilized on PTAA matrices. Parameters of the as-obtained biosensors such as working potential, pH and temperature have been optimized. The amperometric biosensor based on PTAA matrix electrosynthesized in BmimPF6 exhibited wider linear range, lower detection limit, higher sensitivity and bioaffinity, and better operational and storage stability than that electrosynthesized in ACN under optimal conditions. The as-obtained biosensor based on PTAA matrix electrosynthesized in BmimPF6 was employed for the detection of VC content in comme：rcial juices, and the result was close to the data given by manufacturers. Excellent results indicate that the PTAA matrix electrosynthesized in ionic liquid is a promising platform for the covalent immobilization of biologically-active species and the development of biosensors.
基金Supported by the National Natural Science Foundation of China
文摘Pyruvate, a final metabolite of glycogen, is widely distributed over many kinds of tissue fluids of human bodys. The determination for its contents is of clinical importance in gynaecology. Titrimetry, colorimetry and chromatography are common used methods. In recent years, enzymatic mthod has proved to be one of the most important determination techniques for its simplicity and fastness. However, in some cases, the use of purified enzymes as biocatalysts yields systems with a short useful lifetime owing, to enzyme instability A tiss
文摘Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18 靘ol/L glucose with detection limit of 0.5 靘ol/L glucose.
文摘A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by electrochemical and spectroscopic techniques. Results showed that the immobilized HRP exhibited direct electrochemical behavior toward the reduction of H2O2. The resulting biosensor shows a fast amperometric response (<2 s) to H2O2. The linear response range was from 5.0×10-7～1.0×10-5 mol/L with a detection limit of 1.0×10-7mol/L. Moreover, the biosensor has a good reproducibility, and long-term stability.
文摘Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spreeta biosensor kits were used to detect Salmonella Typhimurium on chicken carcass successfully. A taste sensor like electronic tongue or biosensors was used to basically ＂taste＂ the object and differentiated one object from the other with different taste sensor signatures. The surface plasmon resonance biosensor has potential for use in rapid, real-time detection and identification of bacteria, and to study the interaction of organisms with dif- ferent antisera or other molecular species. The selectivity of the SPR biosensor was assayed using a series of antibody con- centrations and dilution series of the organism. The SPR biosensor showed promising to detect the existence of Salmonella Typhimurium at 1 x 106 CFU/ml. Initial results show that the SPR biosensor has the potential for its application in pathogenic bacteria monitoring. However, more tests need to be done to confirm the detection limitation.
基金supported by the National Natural Science Foundation of China(No.20707014)the Program for Young Excellent Talents of Tongji University.
文摘A new strategy using an arnperometric biosensor with Escherichia coli （E. coli） that provides a rapid toxicity determination of chemical compounds is described. The CellSense biosensor system comprises a biological component immobilized in intimate contact with a transducer which converts the biochemical signal into a quantifiable electrical signal. Toxicity assessment of heavy metals using E.coli biosensors could be finished within 30 min and the 50% effective concentrations （ECso） values of four heavy metals were determined. The results shows that inhibitory effects of four heavy metals to E.coli can be ranked in a decreasing order of Hg^2＋ 〉 Cu^2＋ 〉 Zn^2＋ 〉 Ni^2＋, which accords to the results of conventional bacterial counting method. The toxicity test of organic compounds by using CellSense biosensor was also demonstrated. The CellSense biosensor with E. coli shows a good, reproducible behavior and can be used for reproducible measurements.
