An electrochemical sensor for the determination of ronidazole(RNZ) was developed based on a magnetic glassy carbon electrode modified with Al(Ⅲ) doped core-shell magnetic surface molecularly imprinted polymer(MMIP),which was prepared via the sol-gel method using RNZ as template,3-aminopropyltriethoxysilane as functional monomer,orthosilicate as cross-linker,and Al3+ as dopant to generate Lewis acid sites in the silica matrix for the metal coordinate interactions with the template RNZ.The component,morphology of MMIP and the performance of the as prepared sensor were characterized by transmission electron microscopy,Fourier transform infrared spectroscopy,powder X-ray diffraction and the electrochemical methods.Various factors affecting the response behavior of the sensor were studied and optimized.Because of the aluminum doping,the imprinted sensor exhibits the best recognition ability and affinity for RNZ in comparison with the aluminum free MMIP and the non-imprinted one.Under the optimal experimental conditions,the peak currents by differential pulse stripping voltammetry were found to vary linearly with RNZ concentrations in the range of 0.05-50.0 μmol/L with a detection limit of 0.015 μmol/L.This sensor was successfully employed to detect RNZ in milk powder and egg samples with recoveries of 88.6%-97.0%and relative standard deviations of 2.9%-4.6%.