Electrochemical detection of catechol on boron-doped diamond electrode modified with Au/TiO2 nanorod composite

Abstract

Au/TiO2 nanorod composites with different ratios of [TiO 2]:[Au] have been prepared by chemically reducing AuCl 4- on the positively charged TiO2 nanorods surface and used to modify boron-doped diamond (BDD) electrodes. The electrochemical behaviors of catechol on the bare and different Au/TiO 2 nanorod composites-modified BDD electrodes are studied. The cyclic voltammetric results indicate that these different Au/TiO2 nanorod composites-modified BDD electrodes can enhance the electrocatalytic activity toward catechol detection, as compared with the bare BDD electrode. Among these different conditions, the Au/TiO2-BDD3 electrode (the ratio of [TiO2]:[Au] is 27:1) is the most choice for catechol detection. The electrochemical response dependences of the Au/TiO2-BDD3 electrode on pH of solution and the applied potential are studied. The detection limit of catechol is found to be about 1.4 × 10-6 M in a linear range from 5 × 10-6 M to 200 × 10-6 M on the Au/TiO2-BDD3 electrode.