Fabrication of nanoporous Au films with ultra-high surface area for sensitive electrochemical detection of glucose in the presence of Cl−

Nanoporous Au films with ultra-high surface area (roughness factor greater than 1000) were prepared via one-step anodization of Au in citric acid solution. The as-prepared surface of nanoporous Au films was covered with carbonaceous materials, which could be removed by electrochemical methods to produce electrochemically active surfaces. The cleaned nanoporous Au films exhibited high electrochemical activities for glucose oxidation; however, the expansion of the surface area did not necessarily contribute to the sensitivity enhancement in the absence of Cl−. The ultra-high surface area of the nanoporous Au significantly enhanced the sensitivity of the electrochemical detection of glucose in the presence of 100 mM of Cl−, enabling sensitivity as high as 120 μA mM−1 cm−2. Nafion-coated nanoporous Au exhibited a linear amperometric response to glucose with high sensitivity without interference from ascorbic acid. The preparation of nanoporous Au with ultra-high surface area will offer new opportunity for electroanalytical applications based on nanoporous Au structures.