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 anti-fouling 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 μM and from 62.5 to 117.5 μM, with a detection limit of 0.39 μM (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.

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► A facile electrodeposition technique was used to fabricate nano-Au thin films.
► The direct electrochemical behavior is obtained on the immobilized HRP.
► The anti-fouling performance was improved to a great extent by the immobilized HRP.
► An amperometric sensor of 4-CP with an excellent sensing capability was achieved.