title: A double signal electrochemical human immunoglobulin G immunosensor based on gold nanoparticles-polydopamine functionalized reduced graphene oxide as a sensor platform and AgNPs/carbon nanocomposite as signal probe and catalytic substrate.
abstract: In this paper, a double signal electrochemical Human immunoglobulin G (HIgG) immunosensor based on AgNPs/carbon nanocomposite (Ag/C NC) as the signal probe and catalytic substrate was developed for fast and sensitive detection of HIgG. The as-prepared AuNPs-PDA-rGO nanocomposite and Ag/C NC were confirmed by UV-vis, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. Electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical properties of the proposed immunosensor. The AuNPs-PDA-rGO nanocomposite can improve the electron transfer rate and capture more Ab1. In the sandwich-type immunoassay process, the Ag/C NC functionalized bioconjugates were captured on HIgG/Ab1/AuNPs-PDA-rGO surface and the electrochemical double-signal strategy was employed. These double electrochemical detection signals were directly monitored the oxidation current originated from Ag/C NC and indirectly detected the reduction current of benzoquinone which was produced from the reaction of H2O2 and HQ by catalysis of Ag/C NC in electrochemical detection of HIgG. Under the optimized conditions, the current responses were changed with the concentrations of HIgG for the proposed immunosensor with wide linear ranges of 0.1 to 100 ngmL(-1) and 0.01-100 ngmL(-1) with the lowest detection concentration of 0.001 ng mL(-1) in the absence and presence of H2O2 and HQ. The double-signal strategy is used for detection of HIgG, and the results came from the two signals were well consistent with each other. The proposed immunosensor was successfully applied in analysis of human IgG in real samples and this strategy may provide a relative simple and effective method for construction of other immunsensors in detection of other biomarkers in clinical medicine.
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Si
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Huang
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Qiujun
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. Electronic address: liumeilingww@126.com.
authors.forename: Meiling
authors.initials: M
authors.lastname: Liu
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Youyu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation; D001774:Blood Chemical Analysis / Q000295:instrumentation; D002244:Carbon / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000097:blood*; D007211:Indoles / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007211:Indoles; D010087:Oxides; D011108:Polymers; C568283:polydopamine; D002244:Carbon; D006046:Gold; D006108:Graphite
keywords: Ag/C NC; AuNPs-PDA-rGO; Double signal electrochemical immunosensor; Sandwich-type immunoassay