Pyridine-assisted electrodeposition of Au(1 1 1)-dominant gold nanonetworks on glassy carbon electrode for anodic stripping voltammetry analysis of As(III), Se(IV) and Cu(II)

Abstract

Gold nanonetworks with Au(111)-dominant facets (AuNNs(1 1 1)-D) modified glassy carbon electrode (GCE) was simply fabricated by electroreduction of Au(III) with the assistance of pyridine (Py). Cyclic voltammetry of Au(III)-Py complex exhibits two sequential cathodic peaks, reflecting the reduction of Au(III) to Au(I) intermediate and then to Au(0). The as-prepared AuNNs(111)-D/GCE was characterized by scanning electron microcopy, X-ray diffraction and electrochemistry methods, and the results showed that the gold crystalline spread out in a nanonetworks architecture with good distribution, high aspect-ratios, large roughness and 90 % Au(111) facets. The coordination effects of Py, the inferior affinity of Py on Au(111) facets and the sustained generation of Au(I) intermediate contributed to such gold nanoarchitecture. Differential pluse anodic stripping voltammetry analysis of As(III), Se(IV) and Cu(II) was performed on the AuNNs(1 1 1)-D/GCE with high performance. Sensitivity values of 16.9 µA μM−1 (As(III)), 9.51 µA μM−1 (Se(IV)), 6.09 µA μM−1 (Cu(II)), as well as limit of detection values of 0.67 nM (As(III)), 1.1 nM (Se(IV)), 0.53 nM (Cu(II)) were obtained (S/N = 3), respectively. The AuNNs(111)-D/GCE was used for As(III), Se(IV) and Cu(II) determination in real drinkable water samples with satisfied results.