Electrochemical Determination of Copper in Fish Samples

Toxic metal contamination, particularly by copper Cu (II), poses serious risks to environmental and human health due to its persistence, bioaccumulation, and redox-driven toxicity. This study presents a simple, cost-effective, and reliable electrochemical approach for Cu (II) detection using an unmodified screen-printed electrode (SPE). Electrochemical parameters, including supporting electrolyte type and concentration, as well as scan rate, were systematically optimized using cyclic voltammetry. Among various electrolytes tested, 0.1 M potassium chloride (KCl) provided the most stable and sensitive response. The developed method demonstrated a wide linear range (0.25-10.0 mM), excellent precision (RSD≤5.8%), and a limit of detection (LOD) of 0.080 mM. When applied to complex biological matrices, such as fish liver, the sensor achieved high recovery rates (95.10-105.85%), indicating its applicability in real samples. This study also aimed to determine the effectiveness of solid-phase extraction combined with electrochemical detection for identifying Cu (II) in fish liver samples, and to compare its sensitivity and accuracy with that of inductively coupled plasma optical emission spectrometry (ICP-OES). Results demonstrated that unmodified screen-printed electrodes (SPEs) could reliably detect Cu (II) in complex biological matrices, offering a cost-effective and practical alternative for use in environmental and biological monitoring. Compared to other advanced sensors, this method stood out for its minimalistic design, low cost, and operational simplicity, offering a promising alternative for on-site heavy metal detection in resource-limited settings.