Fabrication of Nanoporous Gold Film: A Novel Electrochemical Sensor for Germanium (II)

Abstract

In this work, the fabrication of a high surface area nanoporous gold (NPG) structures on the surface of a gold electrode using a facile and green electrochemical approach via anodization–reduction method for germanium (Ge) determination is presented. The characterization of the NPG was analyzed by cyclic voltammetry, field emission scanning electron microscopy, and X-ray diffraction techniques. Voltammetry showed an improved sensitivity for Ge (II) oxidation at this electrode when compared to a bare electrode, with a peak near to –1.3 V (vs. Ag/AgCl) at a scan rate of 100 mV s⁻¹. The square wave anodic stripping voltammetry shows a response that is linear in the 10–40 μg L⁻¹ Ge (II) concentration range, with a 1.53 μg L⁻¹ limit of detection and 4.65 μg L⁻¹ limit of quantification. The reproducibility and repeatability were assessed, and acceptable performance was achieved.