An electrochemical sensor based on rGO/GaN nanowires for Pb(II) determination

Abstract

In this work, rGO/GaN nanowires electrochemical sensors were fabricated on sapphire substrates by metal organic chemical vapor deposition (MOCVD) and electrodeposition method, and it was used for the detection of Pb²⁺ in water. Reduced graphene oxide (rGO) increases the specific surface area and active sites of gallium nitride nanowires (GaN NW), and GaN NW improves the stability of the rGO, thus a highly sensitive electrochemical sensor was established. Square wave anodic stripping voltammetry (SWASV) was used to detect Pb²⁺. Effects of experimental conditions such as rGO modification amount, pH, Pb²⁺ deposition potential/time on the detection performance were investigated. With optimized detection conditions, the rGO/GaN NW sensor features high sensitivity (0.7362 μA μg^-1 L) in the linear range of 2.5-200 μg L^-1, and the detection limit was 2.5 μg L^-1. Furthermore, the rGO/GaN NW sensor exhibited a good stability and repeatability.