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

Herein, bimetallic Co/Ni-MOF derived hollow NiCoO@C composite modified glassy carbon electrode (NiCoO@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 NiCoO@C has hollow and mesoporous structure, abundant carbon matrixes, sufficient oxygen defects and mixed-valence metallic elements. These advantages make NiCoO@C/GCE show distinguished electrocatalytic performance toward the simultaneous determination of FZD and CAP. The NiCoO@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 NiCoO@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.