Immobilizing Pt nanoparticles and chitosan hybrid film on polyaniline naofibers membrane for an amperometric hydrogen peroxide biosensor

A convenient and effective way for fabricating amperometric hydrogen peroxide (H(2)O(2)) biosensor was designed in this paper. First, the polyaniline (PANI) nanofibers membrane with good conductance and high surface area was electropolymerized on a gold electrode surface. Then, Pt nanoparticle (PtNP) was electrochemically deposited on the PANI nanofibers membrane. Finally, the hybrid film of gold nanoparticle, chitosan, and horseradish peroxidase (HRP) was cast onto the modified electrode to form a stable biofunctional film, which was also employed as a protective layer to PtNP. The proposed biosensor exhibited a rapid response to H(2)O(2) with the linear range from 7.0 x 10(-6) to 1.4 x 10(-2) M and a detection limit of 2.8 x 10(-6) M (S/N = 3). The sensitivity of 558 mu A mM(-1) cm(-2) was obtained. The Michaelis-Menten constant, K(M)(app) value was 1.90 mM suggesting a high affinity. Moreover, it displayed a good reproducibility and long-term stability.