Novel electrochemical sensor for histamine: enhancing food safety with polydopamine-modified crystalline NCU-1 zincophosphate material.

We developed a non-enzymatic sensor for histamine (HIS) detection based on a crystalline zincophosphate framework (NCU-1, referred to as NCU) modified with a self-polymerized polydopamine (PDA) nanolayer on a screen-printed carbon electrode (SPCE). The NCU@PDA core-shell hybrid was synthesized via a one-step self-polymerization technique. The NCU@PDA composite exhibited enhanced electrocatalytic activity for HIS oxidation. The sensor demonstrated a wide linear range of 0.002-0.937 mM, with a detection limit of 0.17 μM (S/N = 3), and a sensitivity of 24.08 μA/mM/cm2, along with good selectivity and stability. Practical applicability was evaluated using histamine-spiked diluted beer, cheese, and fish matrix solutions, yielding satisfactory recoveries. Additional LC-MS analysis of the cheese matrix further supported the accuracy of the spike-recovery results in this complex matrix.