A sensitive enzyme-free electrochemical sensor based on ZnWO 4 @co-MNPC@MIP for specific recognition and determination of chloramphenicol in milk sample

We have carefully built a new chloramphenicol (CAP) electrochemical sensor, which takes the zinc tungstate @ cobalt magnetic nanoporous carbon @ molecularly imprinted polymer (ZnWO @Co-MNPC@MIP) as the core. First, we successfully prepared Co-MNPC nanomaterials using an efficient one-step hydrothermal method and a direct carbonization method. Next, we recombined ZnWO with Co-MNPC and synthesized the completely new ZnWO @Co-MNPC complex by using the hydrothermal method. To further improve its performance, we combined ZnWO @Co-MNPC with a molecular imprinted polymer and coated a molecular imprinted (MIP) shell on the surface of ZnWO @Co-MNPC by precipitation polymerization. This shell not only gives the sensor a new performance but also gives it a stronger peak current, resulting in a more accurate detection of CAP. Under optimal conditions, the ZnWO @Co-MNPC@MIP (MMIP) electrode has a stronger CAP detection peak current than the one-component electrode, with a fairly wide linear range: 0.007-200 μM and 200-1400 μM. Even more surprisingly, the detection limit is as low as 0.0027 μM, which allows the sensor to maintain excellent selectivity and stability in the face of various interferences, making it an excellent electrochemically modified electrode. Compared to magnetic non-molecular imprint sensors (MNIPs), MMIP sensors have higher detection efficiency. After practical application, we found that the ZnWO @Co-MNPC@MIP modified electrode was satisfactory in milk samples.