The Experts below are selected from a list of 1938 Experts worldwide ranked by ideXlab platform
Dianping Tang - One of the best experts on this subject based on the ideXlab platform.
-
enzymatic hydrolysate induced displacement reaction with multifunctional silica beads doped with horseradish peroxidase thionine conjugate for ultrasensitive Electrochemical Immunoassay
Analytical Chemistry, 2015Co-Authors: Youxiu Lin, Dianping Tang, Reinhard Niessner, Qian Zhou, Yuping Lin, Dietmar KnoppAbstract:A novel (invertase) enzymatic hydrolysate-triggered displacement reaction strategy with multifunctional silica beads, doped with horseradish peroxidase–thionine (HRP–Thi) conjugate, was developed for competitive-type Electrochemical Immunoassay of small molecular aflatoxin B1 (AFB1). The competitive-type displacement reaction was carried out on the basis of the affinity difference between enzymatic hydrolysate (glucose) and its analogue (dextran) for concanavalin A (Con A) binding sites. Initially, thionine–HRP conjugates were doped into nanometer-sized silica beads using the reverse micelle method. Then monoclonal anti-AFB1 antibody and Con A were covalently conjugated to the silica beads. The immunosensor was prepared by means of immobilizing the multifunctional silica beads on a dextran-modified sensing interface via the dextran–Con A binding reaction. Gold nanoparticles functionalized with AFB1–bovine serum albumin conjugate (AFB1–BSA) and invertase were utilized as the trace tag. Upon target AFB1 int...
-
layer by layer multienzyme assembly for highly sensitive Electrochemical Immunoassay based on tyramine signal amplification strategy
Biosensors and Bioelectronics, 2014Co-Authors: Guonan Chen, Juan Tang, Jun Zhou, Dianping TangAbstract:Abstract A new sandwich-type Electrochemical immunosensor based on nanosilver-doped bovine serum albumin microspheres (Ag@BSA) with a high ratio of horseradish peroxidase (HRP) and detection antibody was developed for quantitative monitoring of biomarkers (carcinoembryonic antigen, CEA, used in this case) by coupling enzymatic biocatalytic precipitation with tyramine signal amplification strategy on capture antibody-modified glassy carbon electrode. Two immunosensing protocols (with and without tyramine signal amplification) were also investigated for the detection of CEA and improved analytical features were acquired with tyramine signal amplification strategy. With the labeling method, the performance and factors influencing the Electrochemical Immunoassay were studied and evaluated in detail. Under the optimal conditions, the Electrochemical immunosensor exhibited a wide dynamic range of 0.005–80 ng mL−1 toward CEA standards with a low detection limit of 5.0 pg mL−1. Intra- and inter-assay coefficients of variation were below 11%. No significant differences at the 0.05 significance level were encountered in the analysis of 6 clinical serum specimens and 6 spiked new-born cattle serum samples between the Electrochemical Immunoassay and the commercialized electrochemiluminescent Immunoassay method for the detection of CEA.
-
biotin avidin conjugated metal sulfide nanoclusters for simultaneous Electrochemical Immunoassay of tetracycline and chloramphenicol
Mikrochimica Acta, 2014Co-Authors: Bingqian Liu, Guonan Chen, Bing Zhang, Dianping TangAbstract:We report on a protocol for a simultaneous competitive Immunoassay for tetracycline (TC) and chloramphenicol (CAP) on the same sensing interface. Conjugates of TC and of CAP with bovine serum albumin were first co-immobilized on a glassy carbon electrode modified with gold nanoparticles. In parallel, monoclonal anti-TC and anti-CAP antibodies were conjugated onto CdS and PbS nanoclusters, respectively. In a typical assay, the immobilized haptens and the added target analytes competed for binding to the corresponding antibodies on the nanoclusters. Subsequently, Cd(II) and Pb(II) ions are released from the surface of the corresponding nanoclusters by treatment with acid and then were detected by square wave anodic stripping voltammetry. The currents at the peak potentials for Cd(II) and Pb(II) were used as the sensor signal for TC and CAP, respectively. This multiplex Immunoassay enables the simultaneous determination of TC and CAP in a single run with dynamic ranges from 0.01 to 50 ng mL−1 for both analytes. The detection limits for TC and for CAP are 7.5 pg mL−1 and 5.4 pg mL−1, respectively. No obvious nonspecific adsorption and cross-reactivity was observed in a series of analyses. Intra-assay and inter-assay coefficients of variation were less than 10 %. The method was evaluated by analyzing TC and CAP in spiked samples of milk and honey. The recoveries range from 88 % to 107 % for TC, and from 91 % to 119 % for CAP.
-
novel Electrochemical Immunoassay for quantitative monitoring of biotoxin using target responsive cargo release from mesoporous silica nanocontainers
Analytical Chemistry, 2013Co-Authors: Bing Zhang, Guonan Chen, Jiayao Liao, Dianping TangAbstract:A novel homogeneous Immunoassay protocol was designed for quantitative monitoring of small molecular biotoxin (brevetoxin B, PbTx-2, as a model) by using target-responsive cargo release from polystyrene microsphere-gated mesoporous silica nanocontainer (MSN). Initially, monoclonal mouse anti-PbTx-2 capture antibody was covalently conjugated onto the surface of MSN (mAb-MSN), and the electroactive cargo (methylene blue, MB) was then trapped in the pores of mAb-MSN by using aminated polystyrene microspheres (APSM) based on the electrostatic interaction. Upon addition of target PbTx-2, the positively charged APSM was displaced from the negatively charged mAb-MSN because of the specific antigen–antibody reaction. Thereafter, the molecular gate was opened, and the trapped methylene blue was released from the pores. The released methylene blue could be monitored by using a square wave voltammetry (SWV) in a homemade microElectrochemical detection cell. Under optimal conditions, the SWV peak current increased wi...
-
nanogold functionalized dnazyme concatamers with redox active intercalators for quadruple signal amplification of Electrochemical Immunoassay
ACS Applied Materials & Interfaces, 2013Co-Authors: Jun Zhou, Juan Tang, Junyang Zhuang, Dianping TangAbstract:A novel and in situ amplified Immunoassay strategy with quadruple signal amplification was designed for highly efficient Electrochemical detection of low-abundance proteins (carcinoembryonic antigen, CEA, as a model) by using nanogold-functionalized DNAzyme concatamers with redox-active intercalators. To construct such an in situ amplification system, streptavidin-labeled gold nanoparticles (AuNP-SA) were initially used for the labelling of initiator strands (S0) and detection antibody (mAb2) with a large ratio (mAb2–AuNP–S0), and then two auxiliary DNA strands S1 and S2 were designed for in situ propagation of DNAzyme concatamers with the hemin/G-quadruplex format. The quadruple signal amplification was implemented by using the avidin–biotin chemistry, nanogold labels, DNA concatamers, and DNAzymes. In the presence of target CEA, the sandwiched immunocomplex was formed between the immobilized primary antibodies on the electrode and the conjugated detection antibodies on the mAb2–AuNP–S0. The carried S0 i...
Guonan Chen - One of the best experts on this subject based on the ideXlab platform.
-
layer by layer multienzyme assembly for highly sensitive Electrochemical Immunoassay based on tyramine signal amplification strategy
Biosensors and Bioelectronics, 2014Co-Authors: Guonan Chen, Juan Tang, Jun Zhou, Dianping TangAbstract:Abstract A new sandwich-type Electrochemical immunosensor based on nanosilver-doped bovine serum albumin microspheres (Ag@BSA) with a high ratio of horseradish peroxidase (HRP) and detection antibody was developed for quantitative monitoring of biomarkers (carcinoembryonic antigen, CEA, used in this case) by coupling enzymatic biocatalytic precipitation with tyramine signal amplification strategy on capture antibody-modified glassy carbon electrode. Two immunosensing protocols (with and without tyramine signal amplification) were also investigated for the detection of CEA and improved analytical features were acquired with tyramine signal amplification strategy. With the labeling method, the performance and factors influencing the Electrochemical Immunoassay were studied and evaluated in detail. Under the optimal conditions, the Electrochemical immunosensor exhibited a wide dynamic range of 0.005–80 ng mL−1 toward CEA standards with a low detection limit of 5.0 pg mL−1. Intra- and inter-assay coefficients of variation were below 11%. No significant differences at the 0.05 significance level were encountered in the analysis of 6 clinical serum specimens and 6 spiked new-born cattle serum samples between the Electrochemical Immunoassay and the commercialized electrochemiluminescent Immunoassay method for the detection of CEA.
-
biotin avidin conjugated metal sulfide nanoclusters for simultaneous Electrochemical Immunoassay of tetracycline and chloramphenicol
Mikrochimica Acta, 2014Co-Authors: Bingqian Liu, Guonan Chen, Bing Zhang, Dianping TangAbstract:We report on a protocol for a simultaneous competitive Immunoassay for tetracycline (TC) and chloramphenicol (CAP) on the same sensing interface. Conjugates of TC and of CAP with bovine serum albumin were first co-immobilized on a glassy carbon electrode modified with gold nanoparticles. In parallel, monoclonal anti-TC and anti-CAP antibodies were conjugated onto CdS and PbS nanoclusters, respectively. In a typical assay, the immobilized haptens and the added target analytes competed for binding to the corresponding antibodies on the nanoclusters. Subsequently, Cd(II) and Pb(II) ions are released from the surface of the corresponding nanoclusters by treatment with acid and then were detected by square wave anodic stripping voltammetry. The currents at the peak potentials for Cd(II) and Pb(II) were used as the sensor signal for TC and CAP, respectively. This multiplex Immunoassay enables the simultaneous determination of TC and CAP in a single run with dynamic ranges from 0.01 to 50 ng mL−1 for both analytes. The detection limits for TC and for CAP are 7.5 pg mL−1 and 5.4 pg mL−1, respectively. No obvious nonspecific adsorption and cross-reactivity was observed in a series of analyses. Intra-assay and inter-assay coefficients of variation were less than 10 %. The method was evaluated by analyzing TC and CAP in spiked samples of milk and honey. The recoveries range from 88 % to 107 % for TC, and from 91 % to 119 % for CAP.
-
novel Electrochemical Immunoassay for quantitative monitoring of biotoxin using target responsive cargo release from mesoporous silica nanocontainers
Analytical Chemistry, 2013Co-Authors: Bing Zhang, Guonan Chen, Jiayao Liao, Dianping TangAbstract:A novel homogeneous Immunoassay protocol was designed for quantitative monitoring of small molecular biotoxin (brevetoxin B, PbTx-2, as a model) by using target-responsive cargo release from polystyrene microsphere-gated mesoporous silica nanocontainer (MSN). Initially, monoclonal mouse anti-PbTx-2 capture antibody was covalently conjugated onto the surface of MSN (mAb-MSN), and the electroactive cargo (methylene blue, MB) was then trapped in the pores of mAb-MSN by using aminated polystyrene microspheres (APSM) based on the electrostatic interaction. Upon addition of target PbTx-2, the positively charged APSM was displaced from the negatively charged mAb-MSN because of the specific antigen–antibody reaction. Thereafter, the molecular gate was opened, and the trapped methylene blue was released from the pores. The released methylene blue could be monitored by using a square wave voltammetry (SWV) in a homemade microElectrochemical detection cell. Under optimal conditions, the SWV peak current increased wi...
-
dna based hybridization chain reaction for amplified bioelectronic signal and ultrasensitive detection of proteins
Analytical Chemistry, 2012Co-Authors: Bing Zhang, Guonan Chen, Dianping Tang, Reinhard Niessner, Dietmar KnoppAbstract:This work reports a novel Electrochemical Immunoassay protocol with signal amplification for determination of proteins (human IgG here used as a model target analyte) at an ultralow concentration using DNA-based hybridization chain reaction (HCR). The immuno-HCR assay consists of magnetic immunosensing probes, nanogold-labeled signal probes conjugated with the DNA initiator strands, and two different hairpin DNA molecules. The signal is amplified by the labeled ferrocene on the hairpin probes. In the presence of target IgG, the sandwiched immunocomplex can be formed between the immobilized antibodies on the magnetic beads and the signal antibodies on the gold nanoparticles. The carried DNA initiator strands open the hairpin DNA structures in sequence and propagate a chain reaction of hybridization events between two alternating hairpins to form a nicked double-helix. Numerous ferrocene molecules are formed on the neighboring probe, each of which produces an Electrochemical signal within the applied potent...
-
poly o phenylenediamine carried nanogold particles as signal tags for sensitive Electrochemical Immunoassay of prolactin
Analytica Chimica Acta, 2012Co-Authors: Huafeng Chen, Guonan Chen, Bing Zhang, Dianping TangAbstract:Abstract A novel class of redox-active molecular tags, poly(o-phenylenediamine)-carried nanogold particles (GPPDs), was first synthesized and functionalized with horseradish peroxidase-anti-prolactin conjugates (HRP-anti-PRL). Thereafter, a specific sandwich-type Electrochemical Immunoassay was designed for determination of prolactin (PRL) by using GPPD-labeled HRP-anti-PRL conjugates as molecular tags on anti-PRL antibody-modified glassy carbon electrode. Compared with pure gold nanoparticles and poly(o-phenylenediamine) microspheres, the as-prepared GPPDs increased the surface coverage of the nanostructures, and enhanced the immobilization amount of biomolecules. Several labeling protocols compromising GPPD-labeled HRP-anti-PRL, nanogold particles-labeled HRP-anti-PRL and poly(o-phenylenediamine) microspheres-labeled HRP-anti-PRL, were investigated for detection of PRL, and improved analytical features were obtained with the GPPD-based strategy. With the GPPD labeling method, dependence of the Electrochemical signals on the incubation time and pH of the assay solution were also studied. The strong attachment of HRP-anti-PRL to the GPPDs resulted in a good repeatability and intermediate reproducibility down to 9.8%. The dynamic concentration range spanned from 0.5 to 180 ng mL−1 PRL with a detection limit of 0.1 ng mL−1 at the 3Sblank level. No significant differences at the 95% confidence level were encountered in the analysis of 10 spiked blank cattle serum samples between the developed Immunoassay and enzyme-linked immunosorbent assay method for determination of PRL.
Juan Tang - One of the best experts on this subject based on the ideXlab platform.
-
layer by layer multienzyme assembly for highly sensitive Electrochemical Immunoassay based on tyramine signal amplification strategy
Biosensors and Bioelectronics, 2014Co-Authors: Guonan Chen, Juan Tang, Jun Zhou, Dianping TangAbstract:Abstract A new sandwich-type Electrochemical immunosensor based on nanosilver-doped bovine serum albumin microspheres (Ag@BSA) with a high ratio of horseradish peroxidase (HRP) and detection antibody was developed for quantitative monitoring of biomarkers (carcinoembryonic antigen, CEA, used in this case) by coupling enzymatic biocatalytic precipitation with tyramine signal amplification strategy on capture antibody-modified glassy carbon electrode. Two immunosensing protocols (with and without tyramine signal amplification) were also investigated for the detection of CEA and improved analytical features were acquired with tyramine signal amplification strategy. With the labeling method, the performance and factors influencing the Electrochemical Immunoassay were studied and evaluated in detail. Under the optimal conditions, the Electrochemical immunosensor exhibited a wide dynamic range of 0.005–80 ng mL−1 toward CEA standards with a low detection limit of 5.0 pg mL−1. Intra- and inter-assay coefficients of variation were below 11%. No significant differences at the 0.05 significance level were encountered in the analysis of 6 clinical serum specimens and 6 spiked new-born cattle serum samples between the Electrochemical Immunoassay and the commercialized electrochemiluminescent Immunoassay method for the detection of CEA.
-
nanogold functionalized dnazyme concatamers with redox active intercalators for quadruple signal amplification of Electrochemical Immunoassay
ACS Applied Materials & Interfaces, 2013Co-Authors: Jun Zhou, Juan Tang, Junyang Zhuang, Dianping TangAbstract:A novel and in situ amplified Immunoassay strategy with quadruple signal amplification was designed for highly efficient Electrochemical detection of low-abundance proteins (carcinoembryonic antigen, CEA, as a model) by using nanogold-functionalized DNAzyme concatamers with redox-active intercalators. To construct such an in situ amplification system, streptavidin-labeled gold nanoparticles (AuNP-SA) were initially used for the labelling of initiator strands (S0) and detection antibody (mAb2) with a large ratio (mAb2–AuNP–S0), and then two auxiliary DNA strands S1 and S2 were designed for in situ propagation of DNAzyme concatamers with the hemin/G-quadruplex format. The quadruple signal amplification was implemented by using the avidin–biotin chemistry, nanogold labels, DNA concatamers, and DNAzymes. In the presence of target CEA, the sandwiched immunocomplex was formed between the immobilized primary antibodies on the electrode and the conjugated detection antibodies on the mAb2–AuNP–S0. The carried S0 i...
-
sensitive Electrochemical Immunoassay of carcinoembryonic antigen with signal dual amplification using glucose oxidase and an artificial catalase
Analytica Chimica Acta, 2011Co-Authors: Juan Tang, Dianping Tang, Bin Qiu, Guonan ChenAbstract:Abstract A new dual-amplification strategy of Electrochemical signal based on the catalytic recycling of the product was developed for the antigen–antibody interaction by glucose oxidase (GOD)- conjugated gold–silver hollow microspheres (AuAgHSs) coupled with an artificial catalase, Prussian blue nanoparticles (PB), on a graphene-based immunosensing platform. The first signal amplification introduced in this study was based on the labeled GOD on the AuAgHSs toward the catalytic oxidation of glucose. The generated H 2 O 2 was catalytically reduced by the immobilized PB on the graphene nanosheets with the second amplification. With a sandwich-type Immunoassay format, carcinoembryonic antigen (CEA) was monitored as a model analyte by using the synthesized AuAgHSs as labels in pH 6.0 phosphate buffer containing 10 mM glucose. Under optimal conditions, the Electrochemical immunosensor exhibited a wide dynamic range of 0.005–50 ng mL −1 with a low detection limit (LOD) of 1.0 pg mL −1 CEA (at 3 σ ). Both the intra- and inter-assay coefficients of variation (CVs) were lower than 10%. The specificity and stability of the immunosensor were acceptable. In addition, the assay was evaluated for clinical serum specimens, and received a good correlation with those obtained by the referenced electrochemiluminescent (ECL).
-
magneto controlled graphene immunosensing platform for simultaneous multiplexed Electrochemical Immunoassay using distinguishable signal tags
Analytical Chemistry, 2011Co-Authors: Juan Tang, Guonan Chen, Dianping Tang, Reinhard Niessner, Dietmar KnoppAbstract:A novel flow-through multiplexed Immunoassay protocol for simultaneous Electrochemical determination of carcinoembryonic (CEA) and alpha-fetoprotein (AFP) in biological fluids was designed using biofunctionalized magnetic graphene nanosheets (MGO) as immunosensing probes and multifunctional nanogold hollow microspheres (GHS) as distinguishable signal tags. The probes were fabricated by means of co-immobilization of primary anti-CEA (Ab1) and anti-AFP (Ab2) antibodies on the Fe3O4 nanoparticle-coated graphene nanosheets (MGO-Ab1,2). The reverse-micelle method was used for the synthesis of distinguishable signal tags by encapsulation of horseradish peroxide (HRP)-thionine and HRP-ferrocene into nanogold hollow microspheres, respectively, which were utilized as labels of the corresponding GHS-Ab1 and GHS-Ab2. A sandwich-type Immunoassay format was employed for the online detection of CEA and AFP by coupling a flow-through detection cell with an external magnet. The assay was based on the catalytic reduction ...
-
enzyme free Electrochemical Immunoassay with catalytic reduction of p nitrophenol and recycling of p aminophenol using gold nanoparticles coated carbon nanotubes as nanocatalysts
Biosensors and Bioelectronics, 2011Co-Authors: Juan Tang, Jianxin Huang, Dianping Tang, Bin Qiu, Guonan ChenAbstract:A novel enzyme-free sandwich Electrochemical Immunoassay with an ultrahigh sensitivity was developed for detection of alpha-fetoprotein (AFP, as a model analyte) using carbon nanotube-enriched gold nanoparticles (CNT-AuNPs) as nanolabels/nanocatalysts on anti-AFP/glutaraldehyde/thionine-modified glassy carbon electrodes (GCEs). The assays were carried out in a pH 8.0 acetic acid-buffered solution containing 6 mM p-nitrophenol (NP) and 6mM NaBH(4) after the formation of the sandwich-type immunocomplex. Initially, the NP molecules were reduced to p-aminophenol (AP) by the catalysis of the immobilized gold-nanoparticle labels on the CNT-AuNPs with the aid of NaBH(4), then the generated AP molecules were Electrochemically oxidized to p-quinone imine (QI) by an electron mediator of thionine, and then the oxidized QI molecules were reduced back to APs by NaBH(4). The redox cycling of AP and QI continuously increased the signaling, leading to a high sensitivity. Compared with individual gold-nanoparticle labels, the immunosensor using CNT-AuNPs as labels displayed a wider linear range of 8.0×10(-7)-2.0×10(2) ng/mL with a lower detection limit (LOD) of 0.8 fg/mL AFP at a signal-to-noise ratio of 3, which was lower 6 orders than that of commercially available ELISA. Intra-and inter-assay coefficients of variation were below 10%. In addition, the assay was evaluated with clinical serum samples, and no significant differences at the 5% confidence level were encountered in the analysis of real samples between the proposed Immunoassay and commercially available Roche 2010 Electrochemiluminescent Automatic Analyzer for determination of AFP.
Yaqin Chai - One of the best experts on this subject based on the ideXlab platform.
-
new type of redox nanoprobe c60 based nanomaterial and its application in Electrochemical Immunoassay for doping detection
Analytical Chemistry, 2015Co-Authors: Jing Han, Ying Zhuo, Yaqin Chai, Yun Xiang, Ruo YuanAbstract:Carbon nanomaterials were usually exploited as nanocarriers in an Electrochemical immunosensor but rarely acted as redox nanoprobes. Herein, our motivation is to adequately utilize the inner redox activity of fullerene (C60) to obtain a new type of redox nanoprobe based on a hydrophilic C60 nanomaterial. First, C60 nanoparticles (C60NPs) were prepared by phase-transfer method and functionalized with amino-terminated polyamidoamine (PAMAM) to obtain the PAMAM decorated C60NPs (PAMAM-C60NPs) which have better hydrophilicity compared to that of unmodified C60NPs and possesses abundant amine groups for further modification. Following that, gold nanoparticles (nano-Au) were absorbed on the PAMAM-C60NPs surface, and the resultant Au-PAMAM-C60NPs were employed as a new type of redox nanoprobe and nanocarrier to label detection antibodies (Ab2). Doping control has become the biggest problem facing international sport. Erythropoietin (EPO) as a blood doping agent has been a hotspot in doping control. After sandwic...
-
a novel Electrochemical Immunoassay based on diazotization coupled functionalized bioconjugates as trace labels for ultrasensitive detection of carcinoembryonic antigen
Biosensors and Bioelectronics, 2011Co-Authors: Ruo Yuan, Yaqin Chai, Wen Jiang, Huilan SuAbstract:Abstract In this article, a novel sandwich-type Electrochemical immunosensor based on the signal amplification strategy of diazotization-coupling concept for ultrasensitive detection of carcinoembryonic antigen (CEA) was reported. It operates through physisorption of monoclonal anti-CEA on 4-aminothiophenol (4Atp) functionalized gold electrode interface as the detection platform. Diazo-4Atp-coupled-thionine (Thi)-conjugated gold nanoparticles (GNPs) were prepared for immobilization of horseradish peroxidase (HRP) and secondary anti-CEA to form core–shell bioconjugates that were used as Electrochemical signal amplification reagent. The sensitivity of the immunosensor was greatly amplified by a dual amplification: one is that a large number of thionine and HRP was introduced on the electrode surface through sandwich immunoreaction, the other is that HRP as enhancer could catalyze the oxidation reaction of thionine by H2O2, which results in great enhancement of the reduction peak current. Thus, the bioconjugates-based assay provided an amplification approach for detecting CEA at trace levels and led to a detection limit as low as 0.7 pg/mL (at a three times signal-to-noise ratio) that is well-below the threshold value of 2.5 ng/mL for clinical diagnosis. The assay was evaluated for clinical serum samples with various CEA concentrations and received in excellent accordance with the results obtained from the referenced enzyme-linked immunosorbent assay (ELISA).
-
horseradish peroxidase functionalized pt hollow nanospheres and multiple redox probes as trace labels for a sensitive simultaneous multianalyte Electrochemical Immunoassay
Chemical Communications, 2010Co-Authors: Zhongju Song, Ruo Yuan, Ying Zhuo, Yaqin Chai, Wen Jiang, Xin CheAbstract:A novel strategy for a simultaneous multianalyte Electrochemical Immunoassay is proposed using thionine-labeled anti-AFP and ferrocene-labeled anti-CEA as tracers; each biorecognition event yielded a distinct voltammetric peak, whose position and size reflected the identify and level of the corresponding antigen.
-
ultrasensitive Electrochemical immunosensor for clinical Immunoassay using thionine doped magnetic gold nanospheres as labels and horseradish peroxidase as enhancer
Analytical Chemistry, 2008Co-Authors: Dianping Tang, Ruo Yuan, Yaqin ChaiAbstract:A new signal amplification strategy based on thionine (TH)-doped magnetic gold nanospheres as labels and horseradish peroxidase (HRP) as enhancer holds promise to improve the sensitivity and detection limit of the Immunoassay for carcinoembryonic antigen (CEA), as a model protein. This Immunoassay system was fabricated on a carbon fiber microelectrode (CFME) covered with a well-ordered anti-CEA/protein A/nanogold architecture. The reverse micelle method was initially used for the preparation of TH-doped magnetic gold nanospheres (nanospheres), and the synthesized nanospheres were then labeled on HRP-bound anti-CEA as a secondary antibody (bionanospheres). Sandwich-type protocol was successfully introduced to develop a new high-efficiency Electrochemical Immunoassay with the labeled bionanospheres toward the reduction of H2O2. Under optimized conditions, the linear range of the proposed Immunoassay without HRP as enhancer was 1.2−125 ng/mL CEA, whereas the assay sensitivity by using HRP as enhancer could b...
-
Electrochemical Immunoassay for α 1 fetoprotein based on cds nanoparticles and thionine bilayer films modified glass carbon electrode
Biochemical Engineering Journal, 2008Co-Authors: Xiangmin Miao, Ruo Yuan, Yaqin Chai, Yintao Shi, Yanru YuanAbstract:Abstract A novel and effective Electrochemical immunosensor for the rapid determination of α-1-fetoprotein (AFP), based on electrostatic interaction of CdS nanoparticles (nano-CdS) and thionine (Thi) on poly-congo red (PCR) modified glass carbon electrode (GCE), alternately was developed. The formation of the {nano-CdS/Thi + } 2 bilayer films showed a good Electrochemical activity, and a couple of stable and well-defined Thi redox peaks were obtained in pH 7.0 phosphate buffer solution (PBS). Cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) were adopted to confirm the successful stepwise layer-by-layer (LBL) assembly procedure of the immunosensor. Horseradish peroxidase (HRP) was employed to block sites against non-specific binding instead of bovine serum albumin (BSA) and amplify the response currents. Tests showed that the reduction current of the immunosensor was proportional to AFP concentration in the range of 0.30–250.00 ng/mL with a detection limit of 0.12 ng/mL. Moreover, the prepared immunosensor exhibited high sensitivity and good stability, would be valuable for clinical Immunoassay of AFP.
Ruo Yuan - One of the best experts on this subject based on the ideXlab platform.
-
new type of redox nanoprobe c60 based nanomaterial and its application in Electrochemical Immunoassay for doping detection
Analytical Chemistry, 2015Co-Authors: Jing Han, Ying Zhuo, Yaqin Chai, Yun Xiang, Ruo YuanAbstract:Carbon nanomaterials were usually exploited as nanocarriers in an Electrochemical immunosensor but rarely acted as redox nanoprobes. Herein, our motivation is to adequately utilize the inner redox activity of fullerene (C60) to obtain a new type of redox nanoprobe based on a hydrophilic C60 nanomaterial. First, C60 nanoparticles (C60NPs) were prepared by phase-transfer method and functionalized with amino-terminated polyamidoamine (PAMAM) to obtain the PAMAM decorated C60NPs (PAMAM-C60NPs) which have better hydrophilicity compared to that of unmodified C60NPs and possesses abundant amine groups for further modification. Following that, gold nanoparticles (nano-Au) were absorbed on the PAMAM-C60NPs surface, and the resultant Au-PAMAM-C60NPs were employed as a new type of redox nanoprobe and nanocarrier to label detection antibodies (Ab2). Doping control has become the biggest problem facing international sport. Erythropoietin (EPO) as a blood doping agent has been a hotspot in doping control. After sandwic...
-
cation exchange antibody labeling for simultaneous Electrochemical detection of tumor markers ca15 3 and ca19 9
Mikrochimica Acta, 2013Co-Authors: Guangjie Wang, Jinlu Shan, Feng Jin, Yi Qing, Ruo Yuan, Dong WangAbstract:We report on a new kind of non-covalent multi-label Electrochemical Immunoassay that was applied to simultaneously quantify the tumor markers CA15-3 and CA19-9. The method employs a nanohybrid composed of an ionomer and conductive titanium dioxide nanoparticles that act as a matrix support for the antibodies. The two antibodies (anti-CA153 and anti-CA199) were labeled (a) with a cobaltous dipyridine complex, and (b) with methylene blue. Labeling is based on cation-exchange interaction rather than on covalent conjugation. The redox potentials of the two labels are separated by an interval of 0.3 V. The resulting sandwich-type immunosensor was read out by differential pulse voltammetry. The potential sites and currents of the two redox probes reflect the concentration of the two analytes. The two analytes were determined with a detection limit of 1.6 U mL−1 for CA19-9, and of 0.3 U mL−1 for CA15-3.
-
a novel Electrochemical Immunoassay based on diazotization coupled functionalized bioconjugates as trace labels for ultrasensitive detection of carcinoembryonic antigen
Biosensors and Bioelectronics, 2011Co-Authors: Ruo Yuan, Yaqin Chai, Wen Jiang, Huilan SuAbstract:Abstract In this article, a novel sandwich-type Electrochemical immunosensor based on the signal amplification strategy of diazotization-coupling concept for ultrasensitive detection of carcinoembryonic antigen (CEA) was reported. It operates through physisorption of monoclonal anti-CEA on 4-aminothiophenol (4Atp) functionalized gold electrode interface as the detection platform. Diazo-4Atp-coupled-thionine (Thi)-conjugated gold nanoparticles (GNPs) were prepared for immobilization of horseradish peroxidase (HRP) and secondary anti-CEA to form core–shell bioconjugates that were used as Electrochemical signal amplification reagent. The sensitivity of the immunosensor was greatly amplified by a dual amplification: one is that a large number of thionine and HRP was introduced on the electrode surface through sandwich immunoreaction, the other is that HRP as enhancer could catalyze the oxidation reaction of thionine by H2O2, which results in great enhancement of the reduction peak current. Thus, the bioconjugates-based assay provided an amplification approach for detecting CEA at trace levels and led to a detection limit as low as 0.7 pg/mL (at a three times signal-to-noise ratio) that is well-below the threshold value of 2.5 ng/mL for clinical diagnosis. The assay was evaluated for clinical serum samples with various CEA concentrations and received in excellent accordance with the results obtained from the referenced enzyme-linked immunosorbent assay (ELISA).
-
horseradish peroxidase functionalized pt hollow nanospheres and multiple redox probes as trace labels for a sensitive simultaneous multianalyte Electrochemical Immunoassay
Chemical Communications, 2010Co-Authors: Zhongju Song, Ruo Yuan, Ying Zhuo, Yaqin Chai, Wen Jiang, Xin CheAbstract:A novel strategy for a simultaneous multianalyte Electrochemical Immunoassay is proposed using thionine-labeled anti-AFP and ferrocene-labeled anti-CEA as tracers; each biorecognition event yielded a distinct voltammetric peak, whose position and size reflected the identify and level of the corresponding antigen.
-
ultrasensitive Electrochemical immunosensor for clinical Immunoassay using thionine doped magnetic gold nanospheres as labels and horseradish peroxidase as enhancer
Analytical Chemistry, 2008Co-Authors: Dianping Tang, Ruo Yuan, Yaqin ChaiAbstract:A new signal amplification strategy based on thionine (TH)-doped magnetic gold nanospheres as labels and horseradish peroxidase (HRP) as enhancer holds promise to improve the sensitivity and detection limit of the Immunoassay for carcinoembryonic antigen (CEA), as a model protein. This Immunoassay system was fabricated on a carbon fiber microelectrode (CFME) covered with a well-ordered anti-CEA/protein A/nanogold architecture. The reverse micelle method was initially used for the preparation of TH-doped magnetic gold nanospheres (nanospheres), and the synthesized nanospheres were then labeled on HRP-bound anti-CEA as a secondary antibody (bionanospheres). Sandwich-type protocol was successfully introduced to develop a new high-efficiency Electrochemical Immunoassay with the labeled bionanospheres toward the reduction of H2O2. Under optimized conditions, the linear range of the proposed Immunoassay without HRP as enhancer was 1.2−125 ng/mL CEA, whereas the assay sensitivity by using HRP as enhancer could b...