A pioneering electrochemical sensor for the simultaneous determination of nitrofurantoin and furazolidone residues in food and municipal wastewater samples

In this study, a pioneering electrochemical sensor was developed for simultaneously determining nitrofurantoin (NFT) and furazolidone (FZD) residues in food and municipal wastewater samples. The sensor was prepared by integrating gold‑silver-alloy nanocoral clusters (Au-Ag-ANCCs) with zinc oxide nanoparticles (ZnO-NPs), carbon paste electrode (CPE) and polyethylene oxide (PEO) nanocomposites. The surface morphology and elemental compositions of Au-Ag-ANCCs/ZnO-NPs-CPE/PEO were characterized by FT-IR, XRD, SEM, EDX, EIS, and CV. The sensor showed exceptional performance over a wide linear range, from 1.0 pM to 250 μM for NFT and 0.9 nM to 360 μM for FZD. The detection and quantification limits were found to be 0.26 pM and 0.88 pM for NFT and 0.023 pM and 0.076 pM for FZD, respectively. In addition, the sensor exhibited excellent repeatability, reproducibility, selectivity, and long-lasting stability. When applied to the detection of AZM and ENF residues in poultry, fish, honey, dairy products and municipal wastewater, it exhibited excellent recoveries of 96.3–102.8% and relative standard deviations between 1.87% and 1.53%. In general, the developed sensor represents a significant advance in the fight against antibiotic residue pollution.