High-selectively determination of nitric oxide on nanoporous gold electrode

Abstract

Here, a nanoporous gold electrode (NAu) was reported with a unique cone-shape nanohole structure for electrochemical sensing of nitric oxide (NO), which was fabricated via a facile sputtering technique on aluminum oxide membrane. Two kinds of nanoporous gold electrodes fabricated on different aluminum oxide membranes with aperture-size of 20 nm (2020NAu) and 200 nm (2040NAu) were obtained and compared in electrochemically active surface area and electro-oxidation activity. Concerning the determination of NO, it exhibited higher selectivity to NO2− and larger electro-oxidation current on 2020NAu electrode than those on 2040NAu electrode when their backsides were used as sensing interfaces. Meanwhile, the anti-interfering ability of bare 2020NAu electrode was also compared with that on Nafion-modified 2020NAu electrode. Results showed that common electroactive interferents such as H2O2, ascorbic acid, and uric acid could be hindered by cone-shape nanohole structure in the backside of 2020NAu electrode. On the basis of cyclic voltammetry, the linear range was from 4.75 × 10−8 to 9.50 × 10−7 M for NO sensing on 2020NAu electrode.