Signal amplification of electrochemical immunosensor for the detection of human serum IgG using double-codified nanosilica particles as labels.
A simple and sensitive method for in situ amplified electrochemical immunoassay of human serum IgG has been developed by using double-codified nanosilica particles as labels based on horseradish peroxidase-doped nanosilica particles (HRP-SiO(2)) with the conjugation of anti-IgG antibodies (anti-IgG-SiO(2)-HRP). With the sandwich-type immunoassay format, the linear range of the developed immunosensor by using anti-IgG-SiO(2)-HRP as tracer and hydrogen peroxide (H(2)O(2)) as enzyme substrate is 0.01-15 nmol/L IgG with a detection limit of 5.0 pmol/L, while the assay sensitivity by directly using HRP-labeled anti-IgG as secondary antibodies is 1.0-10 nmol/L with a detection limit of 0.1 nmol/L IgG. The reproducibility, stability and specificity of the proposed immunoassay method were acceptable. The IgG concentrations of the clinical serum specimens assayed by the developed immunosensor show consistent results in comparison with those obtained by commercially available enzyme-linked immunosorbent assay (ELISA) method.
Zhong
Zhaoyang
Z
Cancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, PR China.
Li
Mengxia
M
Xiang
Debing
D
Dai
Nan
N
Qing
Ying
Y
Wang
Dong
D
Tang
Dianping
D
D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000097:blood*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D013194:Staining and Labeling / Q000379:methods
D007074:Immunoglobulin G; D012822:Silicon Dioxide