In-situ prepared copper film electrode for adsorptive stripping voltammetric detection of trace Ni(II)

•The first use of copper film electrode (CuFE) for measuring trace Ni(II).•In-situ preparation of CuFE combined with adsorptive cathodic stripping voltammetry.•Operation in mildly alkaline solution without added stabilizing agent for copper ions.•Novel mercury-free sensor for trace metal detection. In this work, we present a copper film electrode (CuFE) as a simple and environmentally-friendly sensor for adsorptive stripping voltammetric detection of trace Ni(II). The CuFE was prepared directly in-situ on a supporting glassy carbon electrode, and revealed excellent electroanalytical performance in a 0.01 M ammonia buffer solution (pH 9.2), without using any stabilizing agent for copper ions. The sensor was used in combination with nioxime as a ligand for Ni(II). After the optimization of several key operational parameters, such as concentration of copper ions, accumulation potential, and accumulation time, the CuFE exhibited good linear response in the examined low concentration range of 1–10 μg L−1 Ni(II) (r2 of 0.995), and low limit of detection (3σ criterion) of 0.2 μg L−1. Finally, its applicability was successfully demonstrated by measuring Ni(II) in a real sample of seawater.