Fabrication and modeling of ultrasensitive label free impedimetric immunosensor for IgG based on poly(o-phenylenediamine) film modified gold electrode

A label free impedimetric immunosensor for IgG with high sensitivity, fine reproducibility and wider linear range was fabricated via immobilizing goat anti-rabbit Immunoglobulin G (IgG) onto Poly(o-phenylenediamine) (PoPD) electropolymerized film modified gold electrode by glutaraldehyde cross-linking. An electrochemical interfacial modeling of biomolecular recognition was constructed and reasonably interpretated. The linear detection concentration ranges of IgG were 0.1~10 ng/mL and 10~100 ng/mL. The detection limit was 0.05 ng/mL(s/n=3). The immunosensor could be reused more than 25 times when renewed by HCl-Glycine buffer solution (pH 2.80).