Fe,Zr-MOF Nanozyme-Enhanced Dual-Recognition System: Integrating Molecularly Imprinted Polymers and Aptamers for Colorimetric Detection of Chlorpyrifos

Chlorpyrifos (CPF) poses severe environmental and health risks, driving the need for on-site monitoring tools. This study presents a novel dual-recognition colorimetric sensor for ultrasensitive detection of CPF by coimmobilizing molecularly imprinted polymers (MIPs) and aptamers onto bimetallic Fe,Zr-MOF composites. The resulting Fe,Zr-MOF/Apt/MIP hybrid synergistically merges the structural robustness of MIPs with the conformational specificity of aptamers, while also functioning as both a nanocarrier and a peroxidase mimic. Notably, CPF binding sterically hinders substrate diffusion to catalytic sites, enabling quantitative detection via dose-dependent inhibition of TMB oxidation. The optimized sensor exhibits exceptional performance: a broad linear range (1–120 ng mL–1), ultralow detection limit (0.105 ng mL–1), and high specificity against interferents. When validated with complex matrices (apples, pears, and cabbage), it achieved satisfactory recoveries (91.0–110.0%). This work establishes a field-deployable strategy for on-site pesticide monitoring in food and environmental safety.