Electrochemical Detection of Catechol on Boron‐doped Diamond Electrode Modified with Au/TiO 2 Nanorod Composite

Au/TiO 2 nanorod composites with different ratios of [TiO 2 ]:[Au] have been prepared by chemically reducing AuCl 4 ‐ on the positively charged TiO 2 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/TiO 2 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/TiO 2 ‐BDD3 electrode (the ratio of [TiO 2 ]:[Au] is 27:1) is the most choice for catechol detection. The electrochemical response dependences of the Au/TiO 2 ‐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/TiO 2 ‐BDD3 electrode.