MOF-derived hollow NiCo2O4/C composite for simultaneous electrochemical determination of furazolidone and chloramphenicol in milk and honey

Herein, bimetallic Co/Ni-MOF derived hollow NiCo2O4@C composite modified glassy carbon electrode (NiCo2O4@C/GCE) is constructed and applied to simultaneously detect furazolidone (FZD) and chloramphenicol (CAP) for the first time. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption–desorption and X-ray photoelectron spectroscopy confirm that NiCo2O4@C has hollow and mesoporous structure, abundant carbon matrixes, sufficient oxygen defects and mixed-valence metallic elements. These advantages make NiCo2O4@C/GCE show distinguished electrocatalytic performance toward the simultaneous determination of FZD and CAP. The NiCo2O4@C/GCE shows wide linear ranges of 0.5–240 µM for FZD and 0.5–320 µM for CAP, low limit of detection of 8.47 nM for FZD and 35 nM for CAP. The mechanism studies show that reductions of FZD and CAP on NiCo2O4@C/GCE are both four-electron and four-proton processes. Moreover, the sensor obtains desirable recoveries for the simultaneous determination of FZD (95.85%–103.9%) and CAP (95.72%–104.4%) in milk and honey by standard addition method.