AIE-Active Hf-MOF as Multifunctional Fluorescent Probe for Detection of Antibiotics, Pesticides and Vitamin B2 in Food.

Abstract

Residual pesticides, antibiotics and vitamins in food matrices pose severe threats to human health and ecological security, and multifunctional fluorescent sensors capable of simultaneous multitarget detection are urgently demanded for rapid residue screening. Herein, two Hf-MOFs were solvothermally assembled from AIE-active tetrakis(4-(4'-carboxyphenyl)phenyl)ethylene (H4ETTC) and Hf6-oxo clusters; solvent tuning affords an 8-connected framework for Hf-MOF-1 and a 12-connected interpenetrated topology for Hf-MOF-2. Notably, Hf-MOF-1 was selected as a versatile fluorescent probe, displaying differentiated luminescent behaviors: fluorescence quenching toward metamitron (MMT) and nitrofurazone (NFZ), luminescence turn-on for moxifloxacin (MXF), and ratiometric fluorescent response toward riboflavin (VB2). The corresponding limits of detection for four analytes reach 1.59 μM, 1.22 μM, 2.32 μM and 0.55 μM, respectively. Anti-interference and cyclic experiments prove its strong antimatrix disturbance and good reusability. Based on spectroscopic, time-resolved fluorescence and theoretical calculations, photoinduced electron transfer, inner-filter effect and other multiple molecular mechanisms collectively mediate the diverse fluorescence-sensing responses. Satisfactory recoveries ranging from 96.3% to 104.2% and RSD below 3.5% in various real food samples confirm its practical applicability. This study enriches high-stability luminescent Hf-MOF resources and supplies a reliable analytical tool for multicontaminant monitoring in food and environmental fields.