A highly soluble poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)/Au nanocomposite for horseradish peroxidase immobilization and biosensing.

A highly soluble poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)/Au (PEDOT-PSS/Au) nanocomposite was prepared via one-step chemical synthesis and the matrix was characterized by UV-vis spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscope (TEM). Due to the excellent aqueous compatibility and biocompatibility, the PEDOT/PSS-Au nanocomposite can be used as biomaterial for enzymes immobilization. In this system, redox enzyme, horseradish peroxidase (HRP) was integrated with PEDOT/PSS-Au nanocomposite and the direct electron transfer of HRP was observed. Moreover, we find that the HRP/PEDOT-PSS/Au modified electrode shows excellent electrocatalytic ability for H(2)O(2) and the formal Michaelis-Menten constant (K(m)(app)) was 0.78 mmol/L. The response currents have good linear relation with the concentrations of H(2)O(2) with a linear range from 2.0 x 10(-7) to 3.8 x 10(-4)mol/L. Copyright (c) 2010 Elsevier B.V. All rights reserved.