Molecularly imprinted electrochemical luminescence sensor based on core–shell magnetic particles with ZIF-8 imprinted material

Abstract A molecularly imprinted electrochemiluminescence (MIP-ECL) sensor with high sensitivity and good structural stability was constructed using the new composite material ZIF-8-NH2 as an imprinted membrane. The ZIF-8-NH2 imprinted composite material was prepared through layer-by-layer self-assembly with carboxyl functionalized magnetic CoFe2O4 nanoparticles as the carrier, ZIF-8-NH2 precursor as the functional monomer, and cinchonine (CCN) as the template molecule. The ZIF-8 MIP@Au@CoFe2O4 core–shell imprinted material was characterized using infrared spectrometry, scanning electron microscopy and X-ray diffraction, and the recognition performance of molecularly imprinted sensor was characterized through electrochemical impedance spectroscopy and electrochemiluminescence (ECL) method. When CCN was re-adsorbed by the imprinted membrane, the ECL intensities of the MIP sensor increased because CCN molecules can promote the ECL intensity of Ru(bpy)32+. As a result, the MIP sensor showed preeminent linear response to CCN in the range of 1.0 × 10-12 –3.1 × 10-8 mol/L, with a detection limit of 7.0 × 10-13 mol/L, which is much lower than that reported for other detection methods. The sensor shows good practicality and can be used to detect CCN in human serum with recoveries ranging from 96.0% to 103.0%.