Portable metal-organic framework alginate beads for high-sensitivity fluorescence detection and effective removal of residual pesticides in fruits and vegetables

Pesticides have been emerged as major organic pollutants in environment, owing to widely spread and intrinsic high toxicity in agricultural productivity. Herein, we designed and synthesized a practicability and portable metal–organic framework (MOF) based composite beads MOF-alginate-Ca²⁺-polyacrylic acid (kgd-M1@ACPs) consist of biocompatible host material (sodium alginate) and fluorescent center with blue emission (where kgd-M1 stands for {[Cd(tbia)·H₂O]·2H₂O}_n), which was further developed for high-efficiency and naked-eye 2,6-dichloro-4-nitroaniline (DCN) monitoring in fruits and vegetables. Significantly, the kgd-M1@ACPs shows obvious fluorescent quench towards toxic pesticide DCN with a low limit of detection (LOD) of 0.09 μM and high recovery from 98.08 to 104.37%. Moreover, the kgd-M1@ACPs also presents an excellent DCN adsorption ability. This work demonstrates that smart material kgd-M1@ACPs is expected to be a good candidate for detection and removal of DCN in real fruits and vegetables, which will present a broad prospect for monitoring and treating pesticides.