MOF-enabled magnetic-fluorescent sensors for on-site organophosphorus/carbamate pesticide detection in fruits and vegetables.

Abstract

Metal organic frameworks (MOFs), with their ultrahigh surface area and tunable pore architectures, have emerged as transformative materials for pesticide residue detection. Herein, we engineered a multifunctional magnetic-fluorescent nanoprobe (Fe3O4@RhB@ZIF90@AChE) for organophosphorus (OPs) and carbamate (CMs) pesticides detection via a one-pot synthesis strategy. Leveraging the pore confinement effect of ZIF90, the platform enhances enzyme-substrate affinity while enabling a cascade signal transduction to produce quantifiable fluorescence inversely proportional to pesticide concentrations. The sensor achieved ultralow detection limits for omethoate (0.015 mg/L), carbofuran (0.020 mg/L), dichlorvos (0.019 mg/L), and trichlorfon (0.021 mg/L) across a broad linear range (0.01-2 mg/L), with exceptional reproducibility (RSD < 3.74 %) and accuracy (spiked recoveries: 97.7-4.5 % in fruits/vegetables). Integrated magnetic separation streamlined detection to 20 min, outperforming conventional methods in speed and operational simplicity. This work pioneers a MOF-based "capture-release-signal" paradigm, offering a field-deployable solution for rapid, high-throughput pesticide screening in agricultural and food safety monitoring.