Ratiometric fluorescence detection of aflatoxin B1 in food samples using metal-organic framework confined within mesoporous silica.

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic mycotoxin that poses significant threats to food safety and human health. A composite material, formed by confining Zr-based metal-organic framework (Zr-LMOF) within aminated mesoporous silica (ASBA-15) and integrating with Ru(bpy)32+, provides a stable and sensitive ratiometric fluorescence-sensing platform for AFB1. The ratiometric detection strategy, based on the fluorescence ratio of 600 nm (Ru(bpy)32+) to 423 nm or 400 nm (Zr-LMOF), significantly improved detection accuracy by suppressing external interferences. The probe achieved a detection limit of 0.2961 ppb and demonstrated excellent performance in real food samples, with recoveries ranging from 97.65% to 105.75% and relative standard deviations below 5%. After obtaining the supernatant extracted from the sample, the fluorescence colorimetric test strip coupled with smartphone imaging enabled on-site, rapid, and portable detection, making this approach highly suitable for food safety monitoring. The study provides a reliable analytical strategy for AFB1 detection, with potential applications in food quality control, environmental monitoring, and public health protection.