Chelation-Based Electrochemical Sensor for Histamine Detection

Histamine is a biogenic amine that is contained in various foods, especially in fish and fish byproducts. Due to its toxicity, the determination of histamine in food is widely evaluated using numerous analytical instruments that are costly and time consuming. This study describes an electrochemical sensor for histamine (HA) detection using screen-printed gold electrodes (AuE) modified with L-cysteine (L-Cys) and copper (Cu(II)). The sensor contains a L-Cys/Cu(II) complex on the electrode surface to detect HA through changes in charge transfer resistance (ΔR ct ). Cyclic voltammetry and electrochemical impedance spectroscopy confirmed the electrode modification. Morphological characterization by atomic force microscopy and scanning electron microscopy revealed a smoother electrode surface after chemical modifications, that also altered the redox response upon HA binding to Cu(II) via its imidazole ring. The sensor responded linearly to HA concentrations from 0.1 to 1 μM (R 2 = 0.9878), with a detection limit of 0.126 μM (S/N = 3). The sensor performed reliably in mixtures of HA with other amines, demonstrating its capability to respond to HA. This work highlights the potential of the AuE/L-Cys/Cu(II) sensor as a fast, low-cost tool for biogenic amines in food safety monitoring.