Mesoporous gold electrodes for sensors based on electrochemical double layer capacitance

SENSORS AND ACTUATORS B-CHEMICAL

卷:123

Article

Mortari, Alessia ; Maaroof, Abbas ; Martin, Donald ; Cortie, Michael B.

关键词: double layer capacitance;    capacitive sensor;    mesoporous gold;    nanoporous gold;    accuracy;    sensitivity;   

DOI  :  10.1016/j.snb.2006.08.018

来源: Elsevier

【 摘 要 】

The use of mesoporous gold as electrode material for measurement of electrochemical capacitance is investigated. The electrodes possess a pore size in the range of 10-30 nm and are prepared by de-alloying films of AuAlx where x >= 2. Analyses conducted with X-ray photoelectron spectra (XPS) show that their surfaces are essentially pure gold, with only traces of aluminium remaining. The electrodes show near-ideal capacitor behaviour under both cyclic voltammetry and potential-step conditions. The higher capacitance of the mesoporous electrodes leads to a better dynamic range in potential-step experiments, resulting in improved accuracy of measurement. The sensitivity of the new material as a capacitive sensor is demonstrated in a milk fouling experiment, and is improved by up to 30 times compared to the control sample of ordinary planar gold. We propose that the use of mesoporous gold electrodes offers a convenient way to sensitively and accurately amplify the capacitance signal of an electrochemical sensor. (c) 2006 Elsevier B.V. All rights reserved.

【 授权许可】

Free