Monitoring levamisole in food and the environment with high selectivity using an electrochemical chiral sensor comprising an MOF and molecularly imprinted polymer

We used an enhanced recognition strategy to fabricate a novel levamisole-detecting chiral electrochemical sensor featuring a metal–organic framework (MOF) combined with a molecularly imprinted polymer (MIP). We first synthesised a Cu/Zn-[benzene-1,3,5-tricarboxylic acid] (Cu/Zn-BTC) MOF as the molecular immobilisation and signal-amplifying unit, and then prepared the MIP (molecular recognition unit) using levamisole as the template on a glassy carbon electrode modified with Cu/Zn-BTC. We obtained a composite chiral sensor with enhanced recognition capability for levamisole after template removal. Using the templated sites as the switch and K3[Fe(CN)6]/K4[Fe(CN)6] as a probe, we established a new method for detecting levamisole in meat products and water bodies. The linear detection range and detection limit of our chiral sensor are 5 to 6000 × 10-11 mol/L and 1.65 × 10−12 mol/L, respectively. Moreover, the sensor exhibited 93.8–109.0% recovery in the detection of levamisole in chicken and other real samples.