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

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 0.1M 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 1mM 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 0.1M PBS (pH 7.4) containing 0.1M 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 0.2V.