Electrochemical immune-biosensor for immunoglobulin G based bioelectrocatalytic reaction on micro-comb electrodes.
A new amplification strategy of electrochemical signaling from antigen-antibody interactions was proposed via back-filling immobilization of horseradish peroxidase (HRP), immunoglobulin G antibodies (anti-IgG) and gold nanoparticles onto a three-dimensional sol-gel (3DSG)-functionalized biorecognition interface. The 3DSG sol-gel network was employed not only as a building block for the surface modification but also as a matrix for ligand functionalization. The signal-amplification was based on the bioelectrocatalytic reaction of the back-filling immobilization of HRP to H(2)O(2). With the non-competitive format, the formation of the antigen-antibody complex by a simple one-step immunoreaction between the immobilized anti-IgG and IgG in sample solution inhibited partly the active center of HRP, and decreased the immobilized HRP towards H(2)O(2) reduction. Under optimal conditions, the proposed immunosensor exhibited a good electrochemical behavior to IgG in a dynamic range of 1.12-162 ng/mL with a detection limit of 0.56 ng/mL (at 3delta). Moreover, the precision, reproducibility and stability of the as-prepared immunosensor were acceptable. Importantly, the proposed methodology would be valuable for diagnosis and monitoring of biomarkers and its metastasis.
Wang
Sheng-Bi
SB
Department of Chemistry, Anshun College, Anshun, People's Republic of China. shengbiwang@hotmail.com
Tang
Dian-Yong
DY
D015374:Biosensing Techniques / Q000295:instrumentation*; D002384:Catalysis; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D008839:Microelectrodes; D008904:Miniaturization; D012680:Sensitivity and Specificity
D007074:Immunoglobulin G