Electrochemical sensing platform for stable detection of trace Cu²⁺ based on ZIF-67/GO/Nafion/GCE

Nanododecahedral ZIF-67 crystals were successfully synthesized by a simple coprecipitation method at room temperature and constructed with graphene oxide (GO) and Nafion as an electrochemical sensing platform for Cu²⁺. The properties of the electrode and the modified materials were analysed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), square wave stripping voltammetry (SWSV), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results show that the ZIF-67/GO/Nafion/GCE sensor platform has a stronger adsorption effect on Cu²⁺. It has high sensitivity (101.29 μA·μM⁻¹) and a low detection limit (7.55 nM) in the linear range of 0.01 to 1.0 μM, as well as long-term stability, good repeatability and selectivity. The recovery rate was between 95.7 and 102.7% for real water samples. The method can be used for the trace analysis of Cu²⁺, which is valuable for the detection of trace metal ions in real water samples.