Amperometric third-generation hydrogen peroxide biosensor based on immobilization of Hb on gold nanoparticles/cysteine/poly(p-aminobenzene sulfonic acid)-modified platinum disk electrode

A novel hydrogen peroxide biosensor was fabricated by self-assembling of hemoglobin (Hb), gold nanoparticles (nano-Au) and l-cysteine (l-cys) on the precursor film formed by electropolymerization of paminobenzene sulfonic acid (p-ABSA) on the platinum disk electrode. Electrochemical impedance spectroscopy (EIS) and UV–vis absorption spectroscopy were employed to characterize the modified process. The performance and factors influencing the resulting biosensor were studied in detail by means of CV and chronoamperometry. The immobilized Hb exhibited direct electrochemical behavior toward the reduction of hydrogen peroxide (H2O2). And the linear range to H2O2 was from 2.1 × 10−7 to 3.1 × 10−3 mol/L with a detection limit of 7.0 × 10−8 mol/L (S/N = 3). In addition, the studied biosensor exhibited good accuracy, high sensitivity.