Three-dimensional graphene gel/carbon cloth electrode for detection of Cu²⁺ through two electrochemical methods of interactive verification

Here, conductive carbon cloth (CC) and three-dimensional (3D) graphene hydrogel (GH) were combined to develop an electrochemical sensor for the detection of trace Cu²⁺. 3D GH/CC has low production cost and high sensitivity, accuracy, and stability, which are suitable for creation of small portable devices and large-scale commercial production. The limit of detection reached 1.87 nmol L⁻¹, and the linear ranges were from 0.1 µmol L⁻¹ to 10 µmol L⁻¹ and from 10 µmol L⁻¹ to 1000 µmol L⁻¹. Innovative interactive verification-based Cu²⁺ detection was carried out using two electrochemical detection methods, namely, anodic stripping voltammetry and electrochemical impedance spectroscopy, and with the mutual support of the two methods, the recovery rate of Cu²⁺ was estimated to 98%, which was improved considerably at medium and low concentrations in the actual water sample. The results showed that this preparation and detection method can be used as a new platform for the detection of trace Cu²⁺ and provide a new commercialized case for evaluating the composition and content of inorganic pollutants in water.