Molecularly imprinted polymer based on metal-organic framework ZIF-67 for high-capacity and high-selectivity adsorption of chloramphenicol in environmental samples

Residual chloramphenicol (CAP) in environment can have adverse effects on health of organism and ecosystems, so accurate detection and effective removal are crucial. Although molecularly imprinted polymers (MIPs) possess excellent selectivity, their pursuit of high specificity often results in relatively low adsorption capacities, restricting their practical application in large-scale pollutant removal. In order to achieve high-capacity and high selectivity adsorption of CAP, in this work, a novel molecularly imprinted polymer (ZIF-67@MIP) was synthesized by using ZIF-67, a metal-organic framework with a high specific surface area, as the carrier. The result demonstrated that the proposed ZIF-67@MIP had a superior adsorption capacity and imprinting factor of 87.80 mg g⁻ 1 and 2.35, respectively. The adsorption equilibrium can be reached within 30 min, which was consistent with the pseudo-second-order kinetic model and Langmuir isothermal model. And that the ZIF-67@MIP had strong anti-interference across a wide range of pH values (3−12) and coexisting ions, making it suitable for complex environmental matrices. Adsorption mechanism analysis verified that the excellent adsorption was attributed to the synergistic effect of π-π stacking, hydrogen bonding, van der Waals forces, hydrophobic interactions, electrostatic attraction, and the spatial matching of imprinted sites. Furthermore, the prepared ZIF-67@MIP was successfully applied to the adsorption and removal of CAP in environmental samples, with recoveries of 80.58 %-106.37 % and a detection limit of 0.001 mg L⁻ 1 . It also exhibited excellent regeneration and stability, maintaining high adsorption efficiency even after 24 cycles. Therefore, the strategy of preparing MIPs by using MOFs as carriers can significantly improve the adsorption performance of imprinting materials, which is of great significance for highly efficient removal of pollutants from the environment.