Application of horseradish peroxidase modified nanostructured Au thin films for the amperometric detection of 4-chlorophenol

A facile electrodeposition method was used to fabricate nanostructured Au thin films. Construction of the amperometric biosensors for 4-chlorophenol (4-CP) is based on the immobilization of horseradish peroxidase (HRP) on the Au thin films via a simple method. The as-prepared nano-Au films provide a favorable microenvironment for the immobilization of HRP and the retention of its activity. With H2O2 as oxidizing co-substrate, the HRP modified electrode displays high catalytic activity toward 4-CP. Besides, it has been demonstrated that the immobilization of HRP has a significant positive effect on the antifouling performance of the electrode material. Furthermore, the enzyme modified electrode was used as a bioelectrochemical sensor of 4-CP, exhibiting linear relationship in two different concentration ranges: from 2.5 to 40 mu M and from 62.5 to 117.5 mu M, with a detection limit of 0.39 mu M (S/N =3) at an applied potential of -0.55 V. The fast current response and good stability were obtained on the HRP modified electrode. (c) 2012 Elsevier B.V. All rights reserved.