Herein,a novel label-free electrochemical immunosensor was fabricated via immobilizing specific anti-β-lactoglobulin(β-LG)antibodies(Abs)onto an integrated electrode of gold nanoparticles(AuNPs)/Prussian blue(PB)/cu...Herein,a novel label-free electrochemical immunosensor was fabricated via immobilizing specific anti-β-lactoglobulin(β-LG)antibodies(Abs)onto an integrated electrode of gold nanoparticles(AuNPs)/Prussian blue(PB)/cubic Ia3d structured mesoporous carbon(CMK-8).This immunosensor allowed for the quantitative detection of the major milk allergenβ-LG.CMK-8 with excellent electrical conductivity and uniformly adjustable pore structure was modified on the glassy carbon electrode(GCE)and served as the sensitive substrate for the electro-polymerization of PB,forming the redox-active layer.AuNPs were subsequently electrochemically deposited on PB/CMK-8/GCE to improve the electrical conductivity and utilized as the connector for Abs immobilization.Duringβ-LG detection,the Abs-modified AuNPs/PB/CMK-8/GCE exhibited a significant reduction in differential pulse voltammetry current signal when exposed toβ-LG,displaying an inverse dose-dependent relationship.The developed electrochemical immunosensor demonstrated good detection performance forβ-LG,with a wider linear range of 0.01-100 ng/mL and a lower detection limit of 4.72 pg/mL.Meanwhile,the sensor exhibited remarkable repeatability,reproducibility,stability and anti-interference capabilities,which was further applied to detectβ-LG in dairy food,achieving satisfactory recoveries(89.2%-98.8%)and lower relative standard deviation(£3.1%).Therefore,this innovative electrochemical method for food allergen detection holds great potential application in food safety determination and evaluation.展开更多
[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus（AIV）.[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid（MPA） to be m...[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus（AIV）.[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid（MPA） to be monolayer on the silver-coated electrode of quartz crystal and coupling the monoclonal antibody to H9 subtype AIV with N-ethy-N＇-（3-dimethyl aminopropyl）carbodiimide hydrochloride（EDC） and N-hydroxysuccinimide（NHS）.The immunosensor to detect H9 subtype AIV was established.[Result] The results showed that the immunosensor displayed better specificity to H9 AIV and had no response to H5AIV and NDV when it was used for detection.The sensitivity test indicated the detection sensitivity for the H9 subtype AIV could reach 20-100 EID50.[Conclusion] The research provided a foundation for further research on the immunosensor for detecting AIV and it could be a new approach to detect other related viruses.展开更多
An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA) was proposed.The operating pH,absorption time,absorption temperature and concentra...An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA) was proposed.The operating pH,absorption time,absorption temperature and concentration of anti-ABA antibody were investigated to optimize the analytical performance.The calibration curve for the determination of ABA was obtained from this impedance immunosensor under optimal conditions.The results showed that the detection limit at about 1 ng/mL in the range of 10-5000 ng/mL...展开更多
A novel multilayer film based on Au nanoparticles(AuNPs) and polyaniline/carboxylated multiwall carbon nanotubes-chitosan nanocomposite(PANI/MWCNTs/CS) was exploited to fabricate a highly sensitive immunosensor for de...A novel multilayer film based on Au nanoparticles(AuNPs) and polyaniline/carboxylated multiwall carbon nanotubes-chitosan nanocomposite(PANI/MWCNTs/CS) was exploited to fabricate a highly sensitive immunosensor for detecting chlorpyrifos. PANI-coated MWCNTs were prepared by in situ chemical polymerization and carboxylated MWCNTs played an important role in obtaining the thin and uniform coating of PANI resulting in the improved immunosensor response. Au NPs were used as a linker to immobilize chlorpyrifos antibody. The performance of the immunosensor was characterized by means of cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and scanning electron microscopy(SEM), respectively. All variables involved in the preparation process and analytical performance of the immunosensor were optimized.Under optimal conditions(antibody concentration: 5 μg/mL, working buffer pH: 6.5, incubation time: 40 min,incubation temperature: 25℃), the immunosensor exhibited a wide linear range from 0.1 to 40× 10^(-6)mg/mL and from 40 × 10^(-6)mg/mL to 500 × 10^(-6)mg/mL, and with a detection limit of 0.06 × 10^(-6)mg/mL, which provided a valuable tool for the chlorpyrifos detection in real samples.展开更多
An electrochemical immunosensor was developed for ultrasensitive detection of microcystin-LR in water. MIL-101, a porous metal-organic frameworks(MOFs) material based on trivalent chromium skeleton were synthesized by...An electrochemical immunosensor was developed for ultrasensitive detection of microcystin-LR in water. MIL-101, a porous metal-organic frameworks(MOFs) material based on trivalent chromium skeleton were synthesized by hydrothermal synthesis method, and loaded with Au nanoparticles(Au NPs) to prepare Au NPs@MIL-101 composite materials which were used as a marker to label anti microcystin-LR(Anti-MC-LR). The composite materials have strong catalytic properties to the oxidation of ascorbic acid. Anti-MC-LR was immobilized on glassy carbon electrode surface using electrodeposition graphene oxide(GO) as an immobilization matrix to construct a competitive microcystin-LR immunosensor. The electrochemical immunosensor display linear relationship in the range of 0.05 ng/mL-75 μg/mL with linear correlation coefficient of 0.9951 and detection limit of 0.02 ng/mL(S/N = 3). This sensor was used to detect microcystin-LR in the water sample. The recovery was 102.43%,which is satisfied. The good testing results indicate the sensor has a great prospect in practical application.展开更多
A micro amperometric immunosensor with the sensitive area of only 1mm^2 was fabricated on silicon using the technique of Micro-Electro-Mechanical Systems (MEMS).A double exposure of SU-8 photoresist process was develo...A micro amperometric immunosensor with the sensitive area of only 1mm^2 was fabricated on silicon using the technique of Micro-Electro-Mechanical Systems (MEMS).A double exposure of SU-8 photoresist process was developed to create both the sensitive pool and reaction pool.Antibody was immobilized via cross-linking with glutaraldehyde on the sensitive area of the electrode surface,which was electropolymerized with polypyrrole previously.The immunosensor was characterized by detection of human immunoglobulin G (HIgG).The immunosensor displayed a good linear response to HIgG concentrations between 5ng/ml and 255ng/ml and demonstrated a fast response time of 3 minutes.展开更多
Convenient,rapid,and accurate detection of cardiac troponin I(cTnI)is crucial in early diagnosis of acute myocardial infarction(AMI).A paper-based electrochemical immunosensor is a promising choice in this field,becau...Convenient,rapid,and accurate detection of cardiac troponin I(cTnI)is crucial in early diagnosis of acute myocardial infarction(AMI).A paper-based electrochemical immunosensor is a promising choice in this field,because of the flexibility,porosity,and cost-efficacy of the paper.However,paper is poor in electronic conductivity and surface functionality.Herein,we report a paper-based electrochemical immunosensor for the label-free detection of cTnI with the working electrode modified by MXene(Ti_(3)C_(2))nanosheets.In order to immobilize the bio-receptor(anti-cTnI)on the MXene-modified working electrode,the MXene nanosheets were functionalized by aminosilane,and the functionalized MXene was immobilized onto the surface of the working electrode through Nafion.The large surface area of the MXene nanosheets facilitates the immobilization of antibodies,and the excellent conductivity facilitates the electron transfer between the electrochemical species and the underlying electrode surface.As a result,the paper-based immunosensor could detect cTnI within a wide range of 5-100 ng/mL with a detection limit of 0.58 ng/mL.The immunosensor also shows outstanding selectivity and good repeatability.Our MXene-modified paper-based electrochemical immunosensor enables fast and sensitive detection of cTnI,which may be used in real-time and cost-efficient monitoring of AMI diseases in clinics.展开更多
Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). H...Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). Hepatitis C shows significant genetic variation in the global population, due to the high rate of viral RNA mutation. There are six variants of the virus(HCV genotypes 1, 2, 3, 4, 5, and 6), with 15 recorded subtypes that vary in prevalence across different regions of the world. A variety of devices are used to diagnose hepatitis C, including HCV antibody test, HCV viral load test, HCV genotype test and liver biopsy. Rapid, inexpensive, sensitive, and robust analytical devices are therefore essential for effective diagnosis and monitoring of disease treatment. This review provides an overview of current electrochemical immunosensor and genosensortechnologies employed in HCV detection.There are a limited number of publications showing electrochemical biosensors being used for the detection of HCV.Due to their simplicity,specificity,and reliability,electrochemical biosensor devices have potential clinical applications in several viral infections.展开更多
By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant...By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor’s resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0×102 colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.展开更多
A new α-fetoprotein-MIP(AFP-MIP) immunosensor based on glass carbon electrode(GCE) modified with polythionine(PTh) and gold nanoparticles(AuNPs) was successfully fabricated for sensitive detection ofα-fetoprotein(AF...A new α-fetoprotein-MIP(AFP-MIP) immunosensor based on glass carbon electrode(GCE) modified with polythionine(PTh) and gold nanoparticles(AuNPs) was successfully fabricated for sensitive detection ofα-fetoprotein(AFP). Through controlling electropolymerization, A "polydopamine(PDA)-AFP" complex was achieved applying AFP as template and dopamine(DA) as imprinted monomers. After elution, the specific cavities can adsorb the target molecules. Using differential pulse voltammetry(DPV) detection,the peak current decreased with the increase in concentration of AFP, and the linear response range of the AFP-MIP immunosensor was from 0.001 ng/mL to 800 ng/mL with the detection limit as low as0.8138 pg/mL. The MIP immunosensor could become a new promising method for the detection of AFP.Furthermore, this MIP sensor was demonstrated in testing AFP in human serum samples with satisfactory results.展开更多
A novel immunosensor based on surface plasmon resonance（SPR） has been developed for the recognition of antigen. The sensor was designed on the basis of the fixed angle of incidence and measuring the reflected intens...A novel immunosensor based on surface plasmon resonance（SPR） has been developed for the recognition of antigen. The sensor was designed on the basis of the fixed angle of incidence and measuring the reflected intensities in a wavelength range of 430--750 nm in real-time. An ultra-bright white light-emitting diode（LED） was used as the light source. Molecular self-assembling in solution was used to form the sensing membrane on gold substrate. It has been seen that the sensitivity of the SPR sensor with 3-mercaptopropionic acid（MPA）/protein A（SPA） sensing membrane is considerably higher than that with MPA or SPA modified sensing membrane. The kinetic processes on the sensing membrane were studied. The human B factor（Bf）, an activator of complement 3（C3）, was recognized among the other antigens. This sensor can also be used for other antigen/antibody or adaptor/receptor recognition. Under optimized experimental conditions, the sensor has good selectivity, repeatability, and reversibility.展开更多
In this study, a novel layer-by-layer polyaniline/graphene （PANi/Gr） structure for electrochemical detec- tion of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition （CVD） method a...In this study, a novel layer-by-layer polyaniline/graphene （PANi/Gr） structure for electrochemical detec- tion of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition （CVD） method and transferred onto the PANi-predeposited microelectrode. The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques. The most attractive feature of this system is a suitable microenvironment, which could provide an amplifi- cation of the conductive signal, thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements. With low detection limit （- 43 × 10 -12 g/L）, ac-ceptable stability and good reproducibility, the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.展开更多
Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assem...Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assemble gold nanopanicles(nanogold)layer,subsequently,a layer of protein G(PG)was immobilized on nanogold layer to further capture antibody orientedly.Compared with the immunosensors using bulky gold electrode and direct PG binding to electrode immobilization technique for antibody,it has attractive advantages,such as miniaturization,good compatibility,broad linear range for human immunoglobulin(HIgG)and easy to be designed into array.展开更多
A novel 2×5 model of insert-plug piezoelectric quartz crystal tumor marker micro-array immunosensor constructed with screw clamp apparatus has been developed for quantitative detection of the tumor markers such a...A novel 2×5 model of insert-plug piezoelectric quartz crystal tumor marker micro-array immunosensor constructed with screw clamp apparatus has been developed for quantitative detection of the tumor markers such as alpha-fetoprotein (AFP),carcino-embryonic antigen (CEA),prostate specific antigen (PSA),and human chorionic gonadotropin (hCG) in serum,in which every crystal unit can oscillate independently with the stability of±1 hertz (Hz) in air and±2 Hz in liquid.These response characteristics of Pz tumor marker micro-array immunosensor such as temperature, time-cost,reproducibility and specificity etc were also investigated.The detection ranges for AFP,CEA,PSA,and hCG obtained by Pz micro-array immunosensor were 20 ng/ml～640 ng/ml,1.56 ng/ml～50 ng/ml,1.25 ng/ml～50 ng/ml,and 2.5 mIU/ml～250 mlU/mi respectively with the coefficient of variance (CV) less than 5%.No cross-reactivates with other tumor markers in serum were observed.The results of AFP,CEA,PSA,and hCG obtained by this method from 68 serum samples were in good agreement with those given by chemiluminescence immunoassay with the correlation coefficients of 0.92,0.90,0.91,and 0.94 respectively.The Pz immunosensor regenerated by urea solution could be reused for five times without appreciable loss of response activity.Therefore,the proposed insert-plug immunosensor provides a rapid, sensitive,specific,reusable,convenient and reliable alternative for the detection of tumor markers in clinical laboratory.展开更多
A novel gold-label silver-stain electrochemical immunosensor was developed based on polythioninegold nanoparticles（PTh-Au） modified glassy carbon electrode（GCE） as a platform and secondary antibody labeled Au NPs...A novel gold-label silver-stain electrochemical immunosensor was developed based on polythioninegold nanoparticles（PTh-Au） modified glassy carbon electrode（GCE） as a platform and secondary antibody labeled Au NPs（Ab;-Au） as immumoprobe for carcinoembryonic antigen（CEA） detection. The sandwich-type biosensor adopted anodic stripping voltammetry to detect silver stripping signal when the Ab;-Au of the formed immunocomplexes were stained with silver. The optimized detection conditions were investigated. The effect of different electrochemical responses at various concentrations of CEA was checked by anodic stripping voltammetry. This immunosensor showed a low detection limit of 0.055 ng/mL and a wide linear calibration of 0.1-120 ng/mL（R;=0.99856）. Moreover, this immunoassay also existed the advantages of good reproducibility, stability and selectivity. Thus, this immunosensing protocol may provide a potential application for effective clinical detection of CEA.展开更多
Advances in sensor technology have allowed the significant progress in the monitoring of noxious compounds in the sea, providing real-time detection so as to prevent risks associated with the diffusion and dispersion ...Advances in sensor technology have allowed the significant progress in the monitoring of noxious compounds in the sea, providing real-time detection so as to prevent risks associated with the diffusion and dispersion of toxic substances in the environment. An important element in the overall picture is the harmful algal blooms which pose serious threats to marine ecosystems through the production of toxins that accumulate in filter-feeders and ultimately impact both human health and fisheries. Domoic acid is a neurotoxic amino acid produced by marine planktonic diatoms of the genus Pseudo-nitzschia. Here we monitored domoic acid production by natural Pseudo-nitzschia populations in phytoplankton samples collected along the Middle Tyrrhenian coast, over the course of one year, using selective immunosensors based on screenprinted electrodes, using differential pulse voltammetry as the electrochemical technique, to yield quantitative outputs. In this work, disposable devices have been applied for monitoring the production of domoic acid on algal extracts and the results have been validated by conventional high pressure liquid chromatography-ultraviolet detection methods. The data obtained revealed the presence of domoic acid in Italian phytoplankton, especially in coastal impacted areas, highlighting the potential risk of toxin entering into marine food webs and the environment. Immunosensors based on screen-printed electrodes prove to be effective tools for annual monitoring of domoic acid in seawater samples, thus providing a reliable early warning system relative to health and economic impact of algal toxins.展开更多
Rapid and accurate detection of immunoglobulin E(Ig E) in serum and reduction of serum dosage are of great significance for clinical detection. Herein, we described a rapid magnetic separation of Ig E from patient ser...Rapid and accurate detection of immunoglobulin E(Ig E) in serum and reduction of serum dosage are of great significance for clinical detection. Herein, we described a rapid magnetic separation of Ig E from patient serum based on Fe3 O4@Si O2-NTA@026 sdab as the capture probe and multiple horseradish peroxidase(HRP)-labeled antibodies linked gold nanoparticles(Au NPs) as chemiluminescence(CL) signal amplifier for ultrasensitive detection of total Ig E. Results showed that the limit of detection of our immunosensor system in serum samples was 0.03 k U/L, which is lowest in comparison with current methods, and far lower than that of Immuno CAP for Ig E detection(0.1 k U/L). Furthermore, our immunosensor possessed satisfied repeatability and accuracy, as well as good stability. In comparison with the Immuno CAP for the quantitative detection of Ig E, highly consistent results were achieved in 20 serum samples. Specially, this method was also successfully utilized for assessing the Ig E traces in breast cancer patients,which provides a new idea for the diagnosis of early cancer. Therefore, we believe that such versatile immunosensor will offer an alternative method for the on-site monitoring and determination of various Ig E-related diseases.展开更多
In this work,we developed a novel photoelectrochemical(PEC)sensor based on n-p organic semiconductor heterojunction for sensitive detecting MCF-7 cancer cells.BTA-C4 Ph and PM6 were designed as photoactive materials t...In this work,we developed a novel photoelectrochemical(PEC)sensor based on n-p organic semiconductor heterojunction for sensitive detecting MCF-7 cancer cells.BTA-C4 Ph and PM6 were designed as photoactive materials to form n-p heterojunction,which greatly enhanced the photoelectric conversion efficiency.Antibody-modified magnetic nanoparticles were utilized to capture and separate MCF-7 cells from samples.Detection of MCF-7 is ascribed to the loading of MCF-7 onto BTA-C4 Ph-PM6 modified electrode that resulted in the decrease of photocurrent intensity.The PEC immunosensor displayed a linear concentration ranging from 50 cell/m L to 1×10^(4) cell/m L with a limit of detection(LOD)of 41 cell/m L(S/N=3)for MCF-7.Additionally,the senor also exhibited good stability,excellent selectivity and prominent reproducibility.Furthermore,the sensor was successfully applied to detect MCF-7 in whole blood.This work illustrates that n-p heterojunction of organic semiconductor may find wide applications for the preparation of different photoelectrochemical sensors.展开更多
Micro fabricated and multilayered perforated cantilever beam immunosensor was modeled using CoventorWare for the estimation of bacterial antigens of Bacillus Anthrax, Pseudomonas aeruginosa, Coryne Bacterium Diptheria...Micro fabricated and multilayered perforated cantilever beam immunosensor was modeled using CoventorWare for the estimation of bacterial antigens of Bacillus Anthrax, Pseudomonas aeruginosa, Coryne Bacterium Diptheria and Treponema pallidum. A rectangular cantilever beam with perforations was simulated with dimensions as length-200 μm, width-10 μm and thickness-0.5 μm. Each perforation is rectangular with length-10 μm, width-5 μm and thickness-0.5 μm. The theoretical and FEM simulations were carried out with five immunoglobulin antibodies, IgA, IgD, IgE, IgG and IgM for the estimation of bacterial antigens. The effect of perforation in cantilever beam and molecular size of antibody and antigen on the performance of the sensor has been studied. The cantilever beam without perforation showed a deflection of 1.8 e + 02 μm whereas the cantilever beam with perforation showed an increase deflection of 1.9 e + 02 μm. With IgG, the difference between analytical and simulation values is positive and low especially with low molecular weight antigens Pseudomonas aeruginosa and Treponema pallidum. The low molecular weight IgG influences the antigen-antibody interaction more fvourably. The simulated perforated rectangular cantilever beam with IgG antibody is a more promising model for the fabrication of a sensor for the estimation of highly motile Pseudomonas aeruginosa and Treponema pallidum.展开更多
Human apolipoprotein E4(APOE4)is an important risk factor for late-onset Alzheimer’s disease(AD).However,little progress has been made for the detection of APOE4,and most of existing detection methods suffer from tim...Human apolipoprotein E4(APOE4)is an important risk factor for late-onset Alzheimer’s disease(AD).However,little progress has been made for the detection of APOE4,and most of existing detection methods suffer from time-consuming process and expensive instruments.This study firstly proposed a simple and sensitive electrochemical method for detection of APOE4 based on carboxyl-rich CeZnO nanoparticles.Under the optimal conditions,the fabricated immunosensor exhibited a good linear relationship ranging from 10 to 100 ng/mL with the detection limit of 1.8 ng/mL(S/N=3).The proposed electrochemical immunosensor had excellent selectivity,reproducibility and stability.Good performance was observed for sensitive determination of APOE4 in human serum sample,which provided a strong support for the detection of APOE4 and early clinical prevention of AD.展开更多
基金supported by the National Natural Science Foundation of China(32272416,31972147)Project of Tianjin Science and Technology Plan(22ZYJDSS00030).
文摘Herein,a novel label-free electrochemical immunosensor was fabricated via immobilizing specific anti-β-lactoglobulin(β-LG)antibodies(Abs)onto an integrated electrode of gold nanoparticles(AuNPs)/Prussian blue(PB)/cubic Ia3d structured mesoporous carbon(CMK-8).This immunosensor allowed for the quantitative detection of the major milk allergenβ-LG.CMK-8 with excellent electrical conductivity and uniformly adjustable pore structure was modified on the glassy carbon electrode(GCE)and served as the sensitive substrate for the electro-polymerization of PB,forming the redox-active layer.AuNPs were subsequently electrochemically deposited on PB/CMK-8/GCE to improve the electrical conductivity and utilized as the connector for Abs immobilization.Duringβ-LG detection,the Abs-modified AuNPs/PB/CMK-8/GCE exhibited a significant reduction in differential pulse voltammetry current signal when exposed toβ-LG,displaying an inverse dose-dependent relationship.The developed electrochemical immunosensor demonstrated good detection performance forβ-LG,with a wider linear range of 0.01-100 ng/mL and a lower detection limit of 4.72 pg/mL.Meanwhile,the sensor exhibited remarkable repeatability,reproducibility,stability and anti-interference capabilities,which was further applied to detectβ-LG in dairy food,achieving satisfactory recoveries(89.2%-98.8%)and lower relative standard deviation(£3.1%).Therefore,this innovative electrochemical method for food allergen detection holds great potential application in food safety determination and evaluation.
基金Supported by the Supporting Program of the"Eleventh Five-year Plan"for Sci&Tech Research of China(2006BAK20A29)Strategical Project for Science and Technology of Guangdong Province(2004A2090102)~~
文摘[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus（AIV）.[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid（MPA） to be monolayer on the silver-coated electrode of quartz crystal and coupling the monoclonal antibody to H9 subtype AIV with N-ethy-N＇-（3-dimethyl aminopropyl）carbodiimide hydrochloride（EDC） and N-hydroxysuccinimide（NHS）.The immunosensor to detect H9 subtype AIV was established.[Result] The results showed that the immunosensor displayed better specificity to H9 AIV and had no response to H5AIV and NDV when it was used for detection.The sensitivity test indicated the detection sensitivity for the H9 subtype AIV could reach 20-100 EID50.[Conclusion] The research provided a foundation for further research on the immunosensor for detecting AIV and it could be a new approach to detect other related viruses.
基金supported by the National Natural Science Foundation of China(No.90817101,30670190 and 3060049)
文摘An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA) was proposed.The operating pH,absorption time,absorption temperature and concentration of anti-ABA antibody were investigated to optimize the analytical performance.The calibration curve for the determination of ABA was obtained from this impedance immunosensor under optimal conditions.The results showed that the detection limit at about 1 ng/mL in the range of 10-5000 ng/mL...
基金supported by the National Natural Science Foundation of China (No. 30972055, 31101286)Agricultural Science and Technology Achievements Transformation Fund Projects of the Ministry of Science and Technology of China (No. 2011GB2C60020)Shandong Provincial Natural Science Foundation, China (No. Q2008D03)
文摘A novel multilayer film based on Au nanoparticles(AuNPs) and polyaniline/carboxylated multiwall carbon nanotubes-chitosan nanocomposite(PANI/MWCNTs/CS) was exploited to fabricate a highly sensitive immunosensor for detecting chlorpyrifos. PANI-coated MWCNTs were prepared by in situ chemical polymerization and carboxylated MWCNTs played an important role in obtaining the thin and uniform coating of PANI resulting in the improved immunosensor response. Au NPs were used as a linker to immobilize chlorpyrifos antibody. The performance of the immunosensor was characterized by means of cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and scanning electron microscopy(SEM), respectively. All variables involved in the preparation process and analytical performance of the immunosensor were optimized.Under optimal conditions(antibody concentration: 5 μg/mL, working buffer pH: 6.5, incubation time: 40 min,incubation temperature: 25℃), the immunosensor exhibited a wide linear range from 0.1 to 40× 10^(-6)mg/mL and from 40 × 10^(-6)mg/mL to 500 × 10^(-6)mg/mL, and with a detection limit of 0.06 × 10^(-6)mg/mL, which provided a valuable tool for the chlorpyrifos detection in real samples.
基金supported by the National Natural Science Foundation of China(Nos. 21165023,21465026, 21765026, 21605130)the National Key Scientific Program of China(Nos. 2011CB911000,01100205020503104)
文摘An electrochemical immunosensor was developed for ultrasensitive detection of microcystin-LR in water. MIL-101, a porous metal-organic frameworks(MOFs) material based on trivalent chromium skeleton were synthesized by hydrothermal synthesis method, and loaded with Au nanoparticles(Au NPs) to prepare Au NPs@MIL-101 composite materials which were used as a marker to label anti microcystin-LR(Anti-MC-LR). The composite materials have strong catalytic properties to the oxidation of ascorbic acid. Anti-MC-LR was immobilized on glassy carbon electrode surface using electrodeposition graphene oxide(GO) as an immobilization matrix to construct a competitive microcystin-LR immunosensor. The electrochemical immunosensor display linear relationship in the range of 0.05 ng/mL-75 μg/mL with linear correlation coefficient of 0.9951 and detection limit of 0.02 ng/mL(S/N = 3). This sensor was used to detect microcystin-LR in the water sample. The recovery was 102.43%,which is satisfied. The good testing results indicate the sensor has a great prospect in practical application.
基金The authors greatly acknowledge the financial support from the National Natural Science Foundation of China （Grant No. 90307014）
文摘A micro amperometric immunosensor with the sensitive area of only 1mm^2 was fabricated on silicon using the technique of Micro-Electro-Mechanical Systems (MEMS).A double exposure of SU-8 photoresist process was developed to create both the sensitive pool and reaction pool.Antibody was immobilized via cross-linking with glutaraldehyde on the sensitive area of the electrode surface,which was electropolymerized with polypyrrole previously.The immunosensor was characterized by detection of human immunoglobulin G (HIgG).The immunosensor displayed a good linear response to HIgG concentrations between 5ng/ml and 255ng/ml and demonstrated a fast response time of 3 minutes.
基金financially supported by the National Key R&D Program of China(2017YFA0204700)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-021)+1 种基金the China-Sweden Joint Mobility Project(51811530018)the Fundamental Research Funds for the Central Universities.
文摘Convenient,rapid,and accurate detection of cardiac troponin I(cTnI)is crucial in early diagnosis of acute myocardial infarction(AMI).A paper-based electrochemical immunosensor is a promising choice in this field,because of the flexibility,porosity,and cost-efficacy of the paper.However,paper is poor in electronic conductivity and surface functionality.Herein,we report a paper-based electrochemical immunosensor for the label-free detection of cTnI with the working electrode modified by MXene(Ti_(3)C_(2))nanosheets.In order to immobilize the bio-receptor(anti-cTnI)on the MXene-modified working electrode,the MXene nanosheets were functionalized by aminosilane,and the functionalized MXene was immobilized onto the surface of the working electrode through Nafion.The large surface area of the MXene nanosheets facilitates the immobilization of antibodies,and the excellent conductivity facilitates the electron transfer between the electrochemical species and the underlying electrode surface.As a result,the paper-based immunosensor could detect cTnI within a wide range of 5-100 ng/mL with a detection limit of 0.58 ng/mL.The immunosensor also shows outstanding selectivity and good repeatability.Our MXene-modified paper-based electrochemical immunosensor enables fast and sensitive detection of cTnI,which may be used in real-time and cost-efficient monitoring of AMI diseases in clinics.
基金Supported by Brazilian funding agencies(Sao Paulo Research Foundation-FAPESP and National Council for Scientific and Technological Development-CNPq)
文摘Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). Hepatitis C shows significant genetic variation in the global population, due to the high rate of viral RNA mutation. There are six variants of the virus(HCV genotypes 1, 2, 3, 4, 5, and 6), with 15 recorded subtypes that vary in prevalence across different regions of the world. A variety of devices are used to diagnose hepatitis C, including HCV antibody test, HCV viral load test, HCV genotype test and liver biopsy. Rapid, inexpensive, sensitive, and robust analytical devices are therefore essential for effective diagnosis and monitoring of disease treatment. This review provides an overview of current electrochemical immunosensor and genosensortechnologies employed in HCV detection.There are a limited number of publications showing electrochemical biosensors being used for the detection of HCV.Due to their simplicity,specificity,and reliability,electrochemical biosensor devices have potential clinical applications in several viral infections.
基金Project supported by the Talent Foundation of Zhejiang Province (No. R205502)the Program of Education Department of Zhejiang Province (No. 20040197), China
文摘By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor’s resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0×102 colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.
基金the National Natural Science Foundation of China (Nos. 61471168, 61571187)China Postdoctoral Science Foundation (No. 2016T90403)+2 种基金Postdoctoral Science Foundation of Jiangsu Province (No. 1601021A)the Natural Science Foundation of Hunan Province (No. 2017JJ209) Hunan Key Research Project (No. 2017SK2174) for the financial supports
文摘A new α-fetoprotein-MIP(AFP-MIP) immunosensor based on glass carbon electrode(GCE) modified with polythionine(PTh) and gold nanoparticles(AuNPs) was successfully fabricated for sensitive detection ofα-fetoprotein(AFP). Through controlling electropolymerization, A "polydopamine(PDA)-AFP" complex was achieved applying AFP as template and dopamine(DA) as imprinted monomers. After elution, the specific cavities can adsorb the target molecules. Using differential pulse voltammetry(DPV) detection,the peak current decreased with the increase in concentration of AFP, and the linear response range of the AFP-MIP immunosensor was from 0.001 ng/mL to 800 ng/mL with the detection limit as low as0.8138 pg/mL. The MIP immunosensor could become a new promising method for the detection of AFP.Furthermore, this MIP sensor was demonstrated in testing AFP in human serum samples with satisfactory results.
基金National Key Technologies Research & Development Program of China(No.2006BAK03A09)National Basic Research Program of China(No.2007CB714503)Science and Technology Development Program of Jilin Province, China (No.20060706)
文摘A novel immunosensor based on surface plasmon resonance（SPR） has been developed for the recognition of antigen. The sensor was designed on the basis of the fixed angle of incidence and measuring the reflected intensities in a wavelength range of 430--750 nm in real-time. An ultra-bright white light-emitting diode（LED） was used as the light source. Molecular self-assembling in solution was used to form the sensing membrane on gold substrate. It has been seen that the sensitivity of the SPR sensor with 3-mercaptopropionic acid（MPA）/protein A（SPA） sensing membrane is considerably higher than that with MPA or SPA modified sensing membrane. The kinetic processes on the sensing membrane were studied. The human B factor（Bf）, an activator of complement 3（C3）, was recognized among the other antigens. This sensor can also be used for other antigen/antibody or adaptor/receptor recognition. Under optimized experimental conditions, the sensor has good selectivity, repeatability, and reversibility.
基金financially supported mainly by the Vietnam National Foundation for Science and Technology Development(No.103.99-2012.15)supported by VAST(VAST03.06/14-15 and VAST.DLT.04/14-15)
文摘In this study, a novel layer-by-layer polyaniline/graphene （PANi/Gr） structure for electrochemical detec- tion of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition （CVD） method and transferred onto the PANi-predeposited microelectrode. The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques. The most attractive feature of this system is a suitable microenvironment, which could provide an amplifi- cation of the conductive signal, thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements. With low detection limit （- 43 × 10 -12 g/L）, ac-ceptable stability and good reproducibility, the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.
基金This work is supported by the National Natural Science Foundation of China （Grant No. 90307014）.
文摘Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assemble gold nanopanicles(nanogold)layer,subsequently,a layer of protein G(PG)was immobilized on nanogold layer to further capture antibody orientedly.Compared with the immunosensors using bulky gold electrode and direct PG binding to electrode immobilization technique for antibody,it has attractive advantages,such as miniaturization,good compatibility,broad linear range for human immunoglobulin(HIgG)and easy to be designed into array.
文摘A novel 2×5 model of insert-plug piezoelectric quartz crystal tumor marker micro-array immunosensor constructed with screw clamp apparatus has been developed for quantitative detection of the tumor markers such as alpha-fetoprotein (AFP),carcino-embryonic antigen (CEA),prostate specific antigen (PSA),and human chorionic gonadotropin (hCG) in serum,in which every crystal unit can oscillate independently with the stability of±1 hertz (Hz) in air and±2 Hz in liquid.These response characteristics of Pz tumor marker micro-array immunosensor such as temperature, time-cost,reproducibility and specificity etc were also investigated.The detection ranges for AFP,CEA,PSA,and hCG obtained by Pz micro-array immunosensor were 20 ng/ml～640 ng/ml,1.56 ng/ml～50 ng/ml,1.25 ng/ml～50 ng/ml,and 2.5 mIU/ml～250 mlU/mi respectively with the coefficient of variance (CV) less than 5%.No cross-reactivates with other tumor markers in serum were observed.The results of AFP,CEA,PSA,and hCG obtained by this method from 68 serum samples were in good agreement with those given by chemiluminescence immunoassay with the correlation coefficients of 0.92,0.90,0.91,and 0.94 respectively.The Pz immunosensor regenerated by urea solution could be reused for five times without appreciable loss of response activity.Therefore,the proposed insert-plug immunosensor provides a rapid, sensitive,specific,reusable,convenient and reliable alternative for the detection of tumor markers in clinical laboratory.
基金financial supports of the National Natural Science Foundation of China(Nos.61471168,61571187)China Postdoctoral Science Foundation(No.2016T90403)+2 种基金Postdoctoral Science Foundation of Jiangsu Province(No.1601021A)the Natural Science Foundation of Hunan Province(No.2017JJ209)Hunan Key Research Project(No.2017SK2174)
文摘A novel gold-label silver-stain electrochemical immunosensor was developed based on polythioninegold nanoparticles（PTh-Au） modified glassy carbon electrode（GCE） as a platform and secondary antibody labeled Au NPs（Ab;-Au） as immumoprobe for carcinoembryonic antigen（CEA） detection. The sandwich-type biosensor adopted anodic stripping voltammetry to detect silver stripping signal when the Ab;-Au of the formed immunocomplexes were stained with silver. The optimized detection conditions were investigated. The effect of different electrochemical responses at various concentrations of CEA was checked by anodic stripping voltammetry. This immunosensor showed a low detection limit of 0.055 ng/mL and a wide linear calibration of 0.1-120 ng/mL（R;=0.99856）. Moreover, this immunoassay also existed the advantages of good reproducibility, stability and selectivity. Thus, this immunosensing protocol may provide a potential application for effective clinical detection of CEA.
文摘Advances in sensor technology have allowed the significant progress in the monitoring of noxious compounds in the sea, providing real-time detection so as to prevent risks associated with the diffusion and dispersion of toxic substances in the environment. An important element in the overall picture is the harmful algal blooms which pose serious threats to marine ecosystems through the production of toxins that accumulate in filter-feeders and ultimately impact both human health and fisheries. Domoic acid is a neurotoxic amino acid produced by marine planktonic diatoms of the genus Pseudo-nitzschia. Here we monitored domoic acid production by natural Pseudo-nitzschia populations in phytoplankton samples collected along the Middle Tyrrhenian coast, over the course of one year, using selective immunosensors based on screenprinted electrodes, using differential pulse voltammetry as the electrochemical technique, to yield quantitative outputs. In this work, disposable devices have been applied for monitoring the production of domoic acid on algal extracts and the results have been validated by conventional high pressure liquid chromatography-ultraviolet detection methods. The data obtained revealed the presence of domoic acid in Italian phytoplankton, especially in coastal impacted areas, highlighting the potential risk of toxin entering into marine food webs and the environment. Immunosensors based on screen-printed electrodes prove to be effective tools for annual monitoring of domoic acid in seawater samples, thus providing a reliable early warning system relative to health and economic impact of algal toxins.
基金supported by the National Key Research and Development Project (No.2020YFA0709900)the National Natural Science Foundation of China (Nos.81871265,81672508,81702617)+4 种基金Key University Science Research Project of Jiangsu Province (No.19KJA520005)Natural Science Basic Research Program of Shaanxi Province (No.2019JM-016)National Natural Science Foundation of Jiangxi Province (No.20202BABL206043)Science and Technology Project of Jiangxi Provincial Health Commission (No.20204495)Open Research Fund of Anhui Key Laboratory of Tobacco。
文摘Rapid and accurate detection of immunoglobulin E(Ig E) in serum and reduction of serum dosage are of great significance for clinical detection. Herein, we described a rapid magnetic separation of Ig E from patient serum based on Fe3 O4@Si O2-NTA@026 sdab as the capture probe and multiple horseradish peroxidase(HRP)-labeled antibodies linked gold nanoparticles(Au NPs) as chemiluminescence(CL) signal amplifier for ultrasensitive detection of total Ig E. Results showed that the limit of detection of our immunosensor system in serum samples was 0.03 k U/L, which is lowest in comparison with current methods, and far lower than that of Immuno CAP for Ig E detection(0.1 k U/L). Furthermore, our immunosensor possessed satisfied repeatability and accuracy, as well as good stability. In comparison with the Immuno CAP for the quantitative detection of Ig E, highly consistent results were achieved in 20 serum samples. Specially, this method was also successfully utilized for assessing the Ig E traces in breast cancer patients,which provides a new idea for the diagnosis of early cancer. Therefore, we believe that such versatile immunosensor will offer an alternative method for the on-site monitoring and determination of various Ig E-related diseases.
基金the National Natural Science Foundation of China(No.22174163)the Hunan Provincial Science and Technology Plan Project,China(No.2019TP1001)the Innovation Driven Project of Central South University(No.2020CX002)。
文摘In this work,we developed a novel photoelectrochemical(PEC)sensor based on n-p organic semiconductor heterojunction for sensitive detecting MCF-7 cancer cells.BTA-C4 Ph and PM6 were designed as photoactive materials to form n-p heterojunction,which greatly enhanced the photoelectric conversion efficiency.Antibody-modified magnetic nanoparticles were utilized to capture and separate MCF-7 cells from samples.Detection of MCF-7 is ascribed to the loading of MCF-7 onto BTA-C4 Ph-PM6 modified electrode that resulted in the decrease of photocurrent intensity.The PEC immunosensor displayed a linear concentration ranging from 50 cell/m L to 1×10^(4) cell/m L with a limit of detection(LOD)of 41 cell/m L(S/N=3)for MCF-7.Additionally,the senor also exhibited good stability,excellent selectivity and prominent reproducibility.Furthermore,the sensor was successfully applied to detect MCF-7 in whole blood.This work illustrates that n-p heterojunction of organic semiconductor may find wide applications for the preparation of different photoelectrochemical sensors.
文摘Micro fabricated and multilayered perforated cantilever beam immunosensor was modeled using CoventorWare for the estimation of bacterial antigens of Bacillus Anthrax, Pseudomonas aeruginosa, Coryne Bacterium Diptheria and Treponema pallidum. A rectangular cantilever beam with perforations was simulated with dimensions as length-200 μm, width-10 μm and thickness-0.5 μm. Each perforation is rectangular with length-10 μm, width-5 μm and thickness-0.5 μm. The theoretical and FEM simulations were carried out with five immunoglobulin antibodies, IgA, IgD, IgE, IgG and IgM for the estimation of bacterial antigens. The effect of perforation in cantilever beam and molecular size of antibody and antigen on the performance of the sensor has been studied. The cantilever beam without perforation showed a deflection of 1.8 e + 02 μm whereas the cantilever beam with perforation showed an increase deflection of 1.9 e + 02 μm. With IgG, the difference between analytical and simulation values is positive and low especially with low molecular weight antigens Pseudomonas aeruginosa and Treponema pallidum. The low molecular weight IgG influences the antigen-antibody interaction more fvourably. The simulated perforated rectangular cantilever beam with IgG antibody is a more promising model for the fabrication of a sensor for the estimation of highly motile Pseudomonas aeruginosa and Treponema pallidum.
基金The National Youth Foundation of China(Grant No.81803487)National Natural Science Foundation(Grant No.81673392)China Postdoctoral Science Foundation(Grant No.2018M631285).
文摘Human apolipoprotein E4(APOE4)is an important risk factor for late-onset Alzheimer’s disease(AD).However,little progress has been made for the detection of APOE4,and most of existing detection methods suffer from time-consuming process and expensive instruments.This study firstly proposed a simple and sensitive electrochemical method for detection of APOE4 based on carboxyl-rich CeZnO nanoparticles.Under the optimal conditions,the fabricated immunosensor exhibited a good linear relationship ranging from 10 to 100 ng/mL with the detection limit of 1.8 ng/mL(S/N=3).The proposed electrochemical immunosensor had excellent selectivity,reproducibility and stability.Good performance was observed for sensitive determination of APOE4 in human serum sample,which provided a strong support for the detection of APOE4 and early clinical prevention of AD.
