ZnO/ZnFe₂O₄ nanocomposite-based electrochemical nanosensors for the detection of furazolidone in pork and shrimp samples: exploring the role of crystallinity, phase ratio, and heterojunction formation

In this study, we have investigated the influence of crystallinity, phase ratio, and heterojunction formation on the sensing performance of ZnO/ZnFe2O4 (ZnO/ZFO) nanocomposite-based electrochemical sensors for the detection of furazolidone (FZD) antibiotic drug. Results obtained show that the crystallinity and phase ratio of ZnO/ZFO nanocomposites have decisive effects on their electron transfer and active site density. Tuning the crystallinity and ZnO content of ZnO/ZFO nanocomposites is an effective way to enhance the FZD electrochemical sensing performance. Findings from this research suggested that the formation of ZnO/ZFO heterojunction could significantly improve their electrochemical responses for FZD due to arising of the internal electric field and redistribution of Zn2+, Fe3+ cations. Under optimized conditions, the ZnO/ZFO-2-based FZD electrochemical sensor reached an electrochemical sensitivity of 0.78 μA μM−1 cm−2 with a LOD of 0.65 μM in the detection range of 1–100 μM. In addition, all these ZnO/ZFO nanocomposites-based electrochemical sensors offer satisfactory repeatability, selectivity, long-term stability, and practical feasibility in pork and shrimp samples. The insights obtained will benefit the future design of ZnFe2O4 nanomaterial-based high-performance electrochemical sensors for monitoring residual antibiotics in real food samples.