A glassy carbon electrode (GCE) was modified with a nanocomposite consisting of multiwalled carbon nanotubes (MWCNTs) loaded with silver-argentous oxide nanoparticles (Ag-Ag2O). The electrode is shown as a viable tool for sensing histamine using differential pulse voltammetry (DPV). The modified GCE, best operated at a potential of 0.97 V (vs. Ag/AgCl) shows higher electrocatalytic activity compared to GCEs modified with MWCNTs or Ag-Ag2O only. Under the optimum conditions, the detection limit is 2 μg⋅L-1 (0.18 μM) and the response is linear in the 5 mg⋅L-1 to 200 mg⋅L-1 histamine concentration range. Sodium chloride, putrescine and cadaverine, commonly present in biological samples and foods, do not interfere. Other performance features include good recoveries, fabrication reproducibility and operational/storage stability. The modified GCE was applied for determination of histamine in fish sauce samples. Graphical abstract A glassy carbon modified with a thin Ag-Ag2O layer decorated on MWCNTs exhibits an enhanced surface area, increasing catalyst interface, and reduced overpotential towards histamine.
Keywords: Electrochemical sensing; Histamine; MWCNTs; Silver-argentous oxide nanoparticles.