Nonenzymatic amperometric response of glucose on a nanoporous gold film electrode fabricated by a rapid and simple electrochemical method

Abstract

An enzyme-free amperometric method was established for glucose detection using a nanoporous gold film (NPGF) electrode prepared by a rapid one-step anodic potential step method within 5 min. The prepared NPGF had an extremely high roughness and was characterized by scanning electron microscopy (SEM) and cyclic voltammetry. Electrochemical responses of the as-prepared NPGF to glucose in 0.1 M phosphate buffer solution (PBS, pH 7.4) with or without Cl − were discussed. In amperometric studies carried out at −0.15 V in the absence of Cl −, the NPGF electrode exhibited a high sensitivity of 232 μA mM −1 cm −2 and gave a linear range from 1 mM up to 14 mM with a detection limit of 53.2 μM (with a signal-to-noise ratio of 3). In addition, the oxidation of ascorbic acid (AA) and uric acid (UA) can be completely eliminated at such a low applied potential. On the other hand, the quantification of glucose in 0.1 M PBS (pH 7.4) containing 0.1 M NaCl offered an extended linear range from 10 μM to 11 mM with a sensitivity of 66.0 μA mM −1 cm −2 and a low detection limit of 8.7 μM (signal-to-noise ratio of 3) at a detection potential of 0.2 V.