Rapid and reliable determination of sulfide and sulfite in food by a multianalyte electrochemical sensor based on nanoporous gold

Given the increasing food safety problems caused by sulfide and sulfite, there is an urgent need to develop a rapid and accurate method for the detection of sulfide and sulfite in food. In this study, a multianalyte electrochemical sensor was successfully fabricated based on glassy carbon electrode (GCE) modified by nanoporous gold (NPG) for the detection of sulfide and sulfite. Owing to the exceptional oxidation activity of NPG towards sulfite and sulfide, the constructed multianalyte NPG/GCE electrochemical sensor achieved highly sensitive detection of sulfide in the concentration range of 50 μM–5 mM with a sensitivity of 21.33 μA mM⁻¹cm⁻² and a limit of detection (LOD) as low as 37.53 μM. For the detection of sulfite, the multianalyte NPG/GCE electrochemical sensor exhibited good linearity in the concentration range of 50 μM–5 mM with a sensitivity of 71.76 μA mM⁻¹cm⁻² and a LOD of 5.12 μM. In addition, the multianalyte NPG/GCE electrochemical sensor realized the reliable detection of sulfide and sulfite in complex real food samples (such as milk, pickles, red wine, and tap water) with high sensitivity and anti-interference ability. The multianalyte NPG/GCE electrochemical sensor exhibited many advantageous properties in practical applications, including easy fabrication, sensitivity, rapidity, cost-efficient, and flexible adaptability, which made it a promising candidate for the rapid and reliable detection of sulfide and sulfite in food.