Amperometric hydrogen peroxide biosensor based on the immobilization of HRP on nano-Au/Thi/poly (p-aminobenzene sulfonic acid)-modified glassy carbon electrode

A novel hydrogen peroxide biosensor was fabricated for the determination of H(2)O(2). The precursor film was first electropolymerized on the glassy carbon electrode with p-aminobenzene sulfonic acid (p-ABSA) by cyclic voltammetry (CV). Then thionine (Thi) was adsorbed to the film to form a composite membrane, which yielded an interface containing amine groups to assemble gold nanoparticles (nano-Au) layer for immobilization of horseradish peroxidase (HRP). The electrochemical characteristics of the biosensor were studied by CV and chronoamperometry. The factors influencing the performance of the resulting biosensor were studied in detail. The biosensor responded to H(2)O(2) in the linear range from 2.6 x 10(-6) mol/L to 8.8 x 10(-3) mol/L with a detection limit of 6.4 x 10(-7) mol/L. Moreover, the studied biosensor exhibited good accuracy and high sensitivity. The proposed method was economical and efficient, making it potentially attractive for the application to real sample analysis.