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Huangxian Ju - One of the best experts on this subject based on the ideXlab platform.
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multiplexed electrochemical Immunoassay using streptavidin nanogold carbon nanohorn as a signal tag to induce silver deposition
Analytica Chimica Acta, 2014Co-Authors: Changrong Zhao, Jie Wu, Huangxian JuAbstract:Abstract An ultrasensitive multiplexed Immunoassay Method was developed by using streptavidin/nanogold/carbon nanohorn (SA/Au/CNH) as a novel signal tag to induce silver enhancement for signal amplification. The Au/CNH was prepared by in situ growth of nanogold on carboxylated CNH and functionalized with streptavidin. The SA/Au/CNH showed well dispersibility in physiological buffer and could sever as a common tracing tag to recognize biotinylated signal antibody. The immunosensor array was prepared on disposable screen-printed electrodes. Through sandwich-type immunoreaction and biotin-streptavidin affinity reaction, the SA/Au/CNH tag was captured on the immunoconjugates to induce silver deposition and amplify the electrochemical stripping signals. Using α-fetoprotein and carcinoembryonic antigen as model analytes, the proposed Method showed wide linear ranges with the detection limits down to 0.024 pg mL −1 and 0.032 pg mL −1 , respectively, and eliminated completely signal cross-talk between adjacent immunosensors. It provided a convenient, high-efficient and ultrasensitive electrochemical detection route for biological analytes, showing great potential in clinical application.
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nanogold mesoporous carbon foam mediated silver enhancement for graphene enhanced electrochemical immunosensing of carcinoembryonic antigen
Biosensors and Bioelectronics, 2014Co-Authors: Jie Wu, Huangxian JuAbstract:Abstract Nanogold functionalized mesoporous carbon foam (Au/MCF) coupling with a signal amplification by C–Au synergistic silver enhancement was designed for sensitive electrochemical immunosensing of biomarker. The Au/MCF was prepared by in situ growth of nanogold on carboxylated MCF and used as a tracing tag to label signal antibody via the inherent interaction between protein and nanogold. The immunosensor was prepared by covalently immobilizing capture antibody on an electrochemically reduced graphene oxide/chitosan film modified glassy carbon electrode. Through a sandwich-type immunoreaction, Au/MCF tags were captured on the immunoconjugates to induce a silver deposition process. The electrochemical stripping signal of the deposited silver was used to monitor the immunoreaction. The Au/MCF-mediated silver enhancement along with the graphene-promoted electron transfer led to high detection sensitivity of carcinoembryonic antigen. Under optimal conditions, the proposed Immunoassay Method showed wide linear range from 0.05 pg mL −1 to 1 ng mL −1 and a detection limit down to 0.024 pg mL −1 . The newly designed amplification strategy holds great potential for ultrasensitive electrochemical biosensing of other analytes.
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chemiluminescence imaging Immunoassay of multiple tumor markers for cancer screening
Analytical Chemistry, 2012Co-Authors: Chen Zong, Jie Wu, Chen Wang, Huangxian JuAbstract:A sensitive chemiluminescence (CL) imaging Immunoassay Method for detection of multiple tumor markers with high throughput, easy operation, and low cost was developed. The immunosensor array was prepared by covalently immobilizing capture antibodies on corresponding sensing sites on a silanized disposable glass chip. Gold nanoparticle-based bioconjugates with a high molar ratio of horseradish peroxidase (HRP) to detection antibodies were used for signal amplification. Under a sandwich Immunoassay, the CL signals triggered by HRP captured on each sensing cell were collected by a charge-coupled device for simultaneous measurement of biomarkers and combination diagnosis of certain tumors. As a proof of concept, the immunosensor array was applied to detect α-fetoprotein, carcinoma antigen 125, carbohydrate antigen 153, and carcinoembryonic antigen and to screen patients with liver, breast, or ovarian cancers. This Method showed wide linear ranges over 5 orders of magnitude and much lower detection limits than...
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ultrasensitive multiplexed Immunoassay with electrochemical stripping analysis of silver nanoparticles catalytically deposited by gold nanoparticles and enzymatic reaction
Analytical Chemistry, 2011Co-Authors: Jie Wu, Chuan Leng, Huangxian JuAbstract:A novel ultrasensitive multiplexed Immunoassay Method was developed by combining alkaline phosphatase (ALP)-labeled antibody functionalized gold nanoparticles (ALP-Ab/Au NPs) and enzyme-Au NP catalyzed deposition of silver nanoparticles at a disposable immunosensor array. The immunosensor array was prepared by covalently immobilizing capture antibodies on chitosan modified screen-printed carbon electrodes. After sandwich-type immunoreactions, the ALP-Ab/Au NPs were captured on an immunosensor surface to catalyze the hydrolysis of 3-indoxyl phosphate, which produced an indoxyl intermediate to reduce Ag+. The silver deposition process was catalyzed by both ALP and Au NPs, which amplified the detection signal. The deposited silver was then measured by anodic stripping analysis in KCl solution. Using human and mouse IgG as model analytes, this multiplexed Immunoassay Method showed wide linear ranges over 4 orders of magnitude with the detection limits down to 4.8 and 6.1 pg/mL, respectively. Acceptable assay ...
Ryoji Kurita - One of the best experts on this subject based on the ideXlab platform.
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N6-Methylation Assessment in Escherichia coli 23S rRNA Utilizing a Bulge Loop in an RNA-DNA Hybrid.
Analytical Chemistry, 2018Co-Authors: Kyoko Yoshioka, Ryoji KuritaAbstract:We propose a sequence-selective assay of N6-methyl-adenosine (m6A) in RNA without PCR or reverse transcription, by employing a hybridization assay with a DNA probe designed to form a bulge loop at the position of a target modified nucleotide. The m6A in the bulge in the RNA–DNA hybrid was assumed to be sufficiently mobile to be selectively recognized by an anti-m6A antibody with a high affinity. By employing a surface-plasmon-resonance measurement or using a microtiter-plate Immunoassay Method, a specific m6A in the Escherichia coli 23S rRNA sequence could be detected at the nanomolar level when synthesized and purified oligo-RNA fragments were used for measurement. We have successfully achieved the first selective detection of m6A2030 specifically in 23S rRNA from real samples of E. coli total RNA by using our immunochemical approach.
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N6-Methylation Assessment in Escherichia coli 23S rRNA Utilizing a Bulge Loop in an RNA–DNA Hybrid
2018Co-Authors: Kyoko Yoshioka, Ryoji KuritaAbstract:We propose a sequence-selective assay of N6-methyl-adenosine (m6A) in RNA without PCR or reverse transcription, by employing a hybridization assay with a DNA probe designed to form a bulge loop at the position of a target modified nucleotide. The m6A in the bulge in the RNA–DNA hybrid was assumed to be sufficiently mobile to be selectively recognized by an anti-m6A antibody with a high affinity. By employing a surface-plasmon-resonance measurement or using a microtiter-plate Immunoassay Method, a specific m6A in the Escherichia coli 23S rRNA sequence could be detected at the nanomolar level when synthesized and purified oligo-RNA fragments were used for measurement. We have successfully achieved the first selective detection of m6A2030 specifically in 23S rRNA from real samples of E. coli total RNA by using our immunochemical approach
Kyoko Yoshioka - One of the best experts on this subject based on the ideXlab platform.
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N6-Methylation Assessment in Escherichia coli 23S rRNA Utilizing a Bulge Loop in an RNA-DNA Hybrid.
Analytical Chemistry, 2018Co-Authors: Kyoko Yoshioka, Ryoji KuritaAbstract:We propose a sequence-selective assay of N6-methyl-adenosine (m6A) in RNA without PCR or reverse transcription, by employing a hybridization assay with a DNA probe designed to form a bulge loop at the position of a target modified nucleotide. The m6A in the bulge in the RNA–DNA hybrid was assumed to be sufficiently mobile to be selectively recognized by an anti-m6A antibody with a high affinity. By employing a surface-plasmon-resonance measurement or using a microtiter-plate Immunoassay Method, a specific m6A in the Escherichia coli 23S rRNA sequence could be detected at the nanomolar level when synthesized and purified oligo-RNA fragments were used for measurement. We have successfully achieved the first selective detection of m6A2030 specifically in 23S rRNA from real samples of E. coli total RNA by using our immunochemical approach.
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N6-Methylation Assessment in Escherichia coli 23S rRNA Utilizing a Bulge Loop in an RNA–DNA Hybrid
2018Co-Authors: Kyoko Yoshioka, Ryoji KuritaAbstract:We propose a sequence-selective assay of N6-methyl-adenosine (m6A) in RNA without PCR or reverse transcription, by employing a hybridization assay with a DNA probe designed to form a bulge loop at the position of a target modified nucleotide. The m6A in the bulge in the RNA–DNA hybrid was assumed to be sufficiently mobile to be selectively recognized by an anti-m6A antibody with a high affinity. By employing a surface-plasmon-resonance measurement or using a microtiter-plate Immunoassay Method, a specific m6A in the Escherichia coli 23S rRNA sequence could be detected at the nanomolar level when synthesized and purified oligo-RNA fragments were used for measurement. We have successfully achieved the first selective detection of m6A2030 specifically in 23S rRNA from real samples of E. coli total RNA by using our immunochemical approach
Jie Wu - One of the best experts on this subject based on the ideXlab platform.
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multiplexed electrochemical Immunoassay using streptavidin nanogold carbon nanohorn as a signal tag to induce silver deposition
Analytica Chimica Acta, 2014Co-Authors: Changrong Zhao, Jie Wu, Huangxian JuAbstract:Abstract An ultrasensitive multiplexed Immunoassay Method was developed by using streptavidin/nanogold/carbon nanohorn (SA/Au/CNH) as a novel signal tag to induce silver enhancement for signal amplification. The Au/CNH was prepared by in situ growth of nanogold on carboxylated CNH and functionalized with streptavidin. The SA/Au/CNH showed well dispersibility in physiological buffer and could sever as a common tracing tag to recognize biotinylated signal antibody. The immunosensor array was prepared on disposable screen-printed electrodes. Through sandwich-type immunoreaction and biotin-streptavidin affinity reaction, the SA/Au/CNH tag was captured on the immunoconjugates to induce silver deposition and amplify the electrochemical stripping signals. Using α-fetoprotein and carcinoembryonic antigen as model analytes, the proposed Method showed wide linear ranges with the detection limits down to 0.024 pg mL −1 and 0.032 pg mL −1 , respectively, and eliminated completely signal cross-talk between adjacent immunosensors. It provided a convenient, high-efficient and ultrasensitive electrochemical detection route for biological analytes, showing great potential in clinical application.
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nanogold mesoporous carbon foam mediated silver enhancement for graphene enhanced electrochemical immunosensing of carcinoembryonic antigen
Biosensors and Bioelectronics, 2014Co-Authors: Jie Wu, Huangxian JuAbstract:Abstract Nanogold functionalized mesoporous carbon foam (Au/MCF) coupling with a signal amplification by C–Au synergistic silver enhancement was designed for sensitive electrochemical immunosensing of biomarker. The Au/MCF was prepared by in situ growth of nanogold on carboxylated MCF and used as a tracing tag to label signal antibody via the inherent interaction between protein and nanogold. The immunosensor was prepared by covalently immobilizing capture antibody on an electrochemically reduced graphene oxide/chitosan film modified glassy carbon electrode. Through a sandwich-type immunoreaction, Au/MCF tags were captured on the immunoconjugates to induce a silver deposition process. The electrochemical stripping signal of the deposited silver was used to monitor the immunoreaction. The Au/MCF-mediated silver enhancement along with the graphene-promoted electron transfer led to high detection sensitivity of carcinoembryonic antigen. Under optimal conditions, the proposed Immunoassay Method showed wide linear range from 0.05 pg mL −1 to 1 ng mL −1 and a detection limit down to 0.024 pg mL −1 . The newly designed amplification strategy holds great potential for ultrasensitive electrochemical biosensing of other analytes.
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chemiluminescence imaging Immunoassay of multiple tumor markers for cancer screening
Analytical Chemistry, 2012Co-Authors: Chen Zong, Jie Wu, Chen Wang, Huangxian JuAbstract:A sensitive chemiluminescence (CL) imaging Immunoassay Method for detection of multiple tumor markers with high throughput, easy operation, and low cost was developed. The immunosensor array was prepared by covalently immobilizing capture antibodies on corresponding sensing sites on a silanized disposable glass chip. Gold nanoparticle-based bioconjugates with a high molar ratio of horseradish peroxidase (HRP) to detection antibodies were used for signal amplification. Under a sandwich Immunoassay, the CL signals triggered by HRP captured on each sensing cell were collected by a charge-coupled device for simultaneous measurement of biomarkers and combination diagnosis of certain tumors. As a proof of concept, the immunosensor array was applied to detect α-fetoprotein, carcinoma antigen 125, carbohydrate antigen 153, and carcinoembryonic antigen and to screen patients with liver, breast, or ovarian cancers. This Method showed wide linear ranges over 5 orders of magnitude and much lower detection limits than...
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ultrasensitive multiplexed Immunoassay with electrochemical stripping analysis of silver nanoparticles catalytically deposited by gold nanoparticles and enzymatic reaction
Analytical Chemistry, 2011Co-Authors: Jie Wu, Chuan Leng, Huangxian JuAbstract:A novel ultrasensitive multiplexed Immunoassay Method was developed by combining alkaline phosphatase (ALP)-labeled antibody functionalized gold nanoparticles (ALP-Ab/Au NPs) and enzyme-Au NP catalyzed deposition of silver nanoparticles at a disposable immunosensor array. The immunosensor array was prepared by covalently immobilizing capture antibodies on chitosan modified screen-printed carbon electrodes. After sandwich-type immunoreactions, the ALP-Ab/Au NPs were captured on an immunosensor surface to catalyze the hydrolysis of 3-indoxyl phosphate, which produced an indoxyl intermediate to reduce Ag+. The silver deposition process was catalyzed by both ALP and Au NPs, which amplified the detection signal. The deposited silver was then measured by anodic stripping analysis in KCl solution. Using human and mouse IgG as model analytes, this multiplexed Immunoassay Method showed wide linear ranges over 4 orders of magnitude with the detection limits down to 4.8 and 6.1 pg/mL, respectively. Acceptable assay ...
Feng Yan - One of the best experts on this subject based on the ideXlab platform.
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multilayer hemin g quadruplex wrapped gold nanoparticles as tag for ultrasensitive multiplex Immunoassay by chemiluminescence imaging
Biosensors and Bioelectronics, 2013Co-Authors: Chen Zong, Feng YanAbstract:A multilayer hemin/G-quadruplex DNAzyme wrapped gold nanoparticle (M-DNAzyme/AuNP) tag was designed for ultrasensitive chemiluminescence (CL) imaging. By combining with a disposable protein array, an ultrasensitive and high-throughput multiplex CL Immunoassay Method was proposed for simultaneous detection of four cancer biomarkers. The M-DNAzyme/AuNP tag was prepared by assembling high ratio of alkylthiol-capped signal DNA containing multiple G-quadruplex sequences to biotinylated DNA on AuNPs and then reacting with hemin to form multilayer hemin/G-quadruplex DNAzyme units. It could be bound to the biotinylated secondary antibody of sandwich immunocomplex by biotin–streptavidin conjugation to catalyze a CL reaction on a protein array, which produced strong CL emission. Under optimal conditions, the CL signals could be simultaneously collected by a charge-coupled device for ultrasensitive multiplex CL imaging of cancer biomarkers. Using α-fetoprotein, human chorionic gonadotrophin-β, carcinoma antigen 125, and carcinoembryonic antigen as model analytes, the proposed Immunoassay Method showed high sensitivities and wide linear ranges in a simple, cheap and high throughput way. The M-DNAzyme/AuNP as a universal signal tag as well as the protein chip could be suitable for mass production for economical, portable and multianalyte assay, showing a promising potential in application to clinic and other relative fields.
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ultrasensitive Immunoassay of protein biomarker based on electrochemiluminescent quenching of quantum dots by hemin bio bar coded nanoparticle tags
Analytical Chemistry, 2011Co-Authors: Dajie Lin, Feng Yan, Shengyuan DengAbstract:A hemin bio-bar-coded nanoparticle probe labeled antibody was designed by the assembly of antibody and alkylthiol-capped bar-code G-quadruplex DNA on gold nanoparticles and the interaction of hemin with the DNA to form a G-quadruplex/hemin bio-bar-code. An ultrasensitive Immunoassay Method was developed by combining the labeled antibody with an electrochemiluminescent (ECL) immunosensor for protein. The ECL immunosensor was constructed by a layer-by-layer modification of carbon nanotubes, CdS quantum dots (QDs), and capture antibody on a glassy carbon electrode. In air-saturated pH 8.0 PBS the immunosensor showed a carbon-nanotube-enhanced cathodic ECL emission of QDs. Upon the formation of immunocomplex, the ECL intensity decreased owing to the consumption of ECL coreactant in bio-bar-code electrocatalyzed reduction of dissolved oxygen. Using α-fetoprotein as model analyte, the quenched ECL could be used for Immunoassay with a linear range of 0.01 pg mL–1 to 1 ng mL–1 and a detection limit of 1.0 fg mL–1...
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dual signal amplification of glucose oxidase functionalized nanocomposites as a trace label for ultrasensitive simultaneous multiplexed electrochemical detection of tumor markers
Analytical Chemistry, 2009Co-Authors: Guosong Lai, Feng YanAbstract:A novel tracer, glucose oxidase-functionalized nanocomposite, was designed to label the signal antibodies for ultrasensitive multiplexed measurement of tumor markers using a disposable immunosensor array. The immunosensor array was constructed by coating layer-by-layer colloidal Prussian blue (PB), gold nanoparticles, and capture antibodies on screen-printed carbon electrodes. The preparation of glucose oxidase-functionalized nanocomposites and the labeling of antibody were performed by one-pot assembly of glucose oxidase and antibody on gold nanoparticles attached carbon nanotubes. The PB immobilized on immunosensor surface acted as a mediator to catalyze the reduction of H2O2 produced in the enzymatic cycle. Both the high-content glucose oxidase and carbon nanotubes in the tracer amplified the detectable signal for the sandwich-type Immunoassay. Using carcinoembryonic antigen and α-fetoprotein as model analytes, the simultaneous multiplexed Immunoassay Method using the immunosensor array and the designe...
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a disposable electrochemical immunosensor for flow injection Immunoassay of carcinoembryonic antigen
Biosensors and Bioelectronics, 2006Co-Authors: Jinhai Tang, Zong Dai, Feng Yan, Nabil El MurrAbstract:A new simple Immunoassay Method for carcinoembryonic antigen (CEA) detection using a disposable immunosensor coupled with a flow injection system was developed. The immunosensor was prepared by coating CEA/colloid Au/chitosan membrane at a screen-printed carbon electrode (SPCE). Using a competitive Immunoassay format, the immunosensor inserted in the flow system with an injection of sample and horseradish peroxidase (HRP)-labeled CEA antibody was used to trap the labeled antibody at room temperature for 35 min. The current response obtained from the labeled HRP to thionine–H2O2 system decreased proportionally to the CEA concentration in the range of 0.50–25 ng/ml with a correlation coefficient of 0.9981 and a detection limit of 0.22 ng/ml (S/N = 3). The Immunoassay system could automatically control the incubation, washing and current measurement steps with good stability and acceptable accuracy. Thus, the proposed Method proved its potential use in clinical Immunoassay of CEA. © 2005 Elsevier B.V. All rights reserved.
