A mediatorless and label-free amperometric immunosensor for detection of h-IgG.
A novel experimental methodology for studying a mediatorless and label-free immunosensor is proposed by immobilizing antibody on gold nanoparticle/L-cysteine coated electrode (nano-Au/L-cysteine electrode). Differential pulse voltammograms (DPV) resulting from the assembled immunosensor indicate that the immunosensor shows excellent electrochemical response to dopamine so that the electrochemical response is utilized for the signal generation step of the immunosensor. Therefore, by means of unenzymatic-labeling procedure combined with the amperometric detection using dopamine as substrate, the immunological reaction can be detected. After the immunosensor is incubated with h-IgG solution, the access of electrocatalytic behavior center of the immunosensor to dopamine is partly inhibited, which leads to a linear decrease in amperometric response of the immunosensor with h-IgG concentration over a range 0.82-90 ng mL(-1) by DPV.
Chongqing Institutions of Higher Learning Center of Forensic Science Engineering and Research, Forensic Identification Center, College of Criminal Investigation Law, Southwest University of Political Science and Law, Chongqing 401120, China.
Lingyan
L
Zhang
Yan
Y
Liu
Tao
T
Chen
D000906:Antibodies / Q000276:immunology*; D004298:Dopamine; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006046:Gold; D006801:Humans; D007118:Immunoassay; D007074:Immunoglobulin G / Q000276:immunology*; D053758:Nanoparticles
D000906:Antibodies; D007074:Immunoglobulin G; D006046:Gold; D004298:Dopamine