One stone two birds: NH2-UiO-66@MB-based bimodal aptasensor for sensitive and rapid detection of zearalenone in cereal products

Zearalenone (ZEN), a prevalent mycotoxin found in cereal crops, poses a significant threat to food safety and human health. To address this issue, there is an urgent need for rapid, sensitive, and cost-effective detection methods. In this study, we developed a novel bimodal aptasensor based on NH₂-UiO-66@MB composites for ZEN detection. Methylene blue (MB) was encapsulated within NH₂-UiO-66 nanoparticles to enhance fluorescence intensity, and the ZEN aptamer was attached to NH₂-UiO-66 via Zr–O–P bonds and Coulombic forces to create a gating effect. In the presence of ZEN, the aptamer bounded to ZEN, triggering a conformational change that released MB, resulting in decreased fluorescence intensity and absorbance. Under optimal conditions, the bimodal aptasensor exhibited wide linear ranges (2.5–300 ng/mL for colorimetry and 0.125–200 ng/mL for fluorescence) and low limits of detection (1.16 ng/mL for colorimetry and 0.03 ng/mL for fluorescence). Furthermore, the aptasensor demonstrated high specificity and reproducibility, with recovery rates ranging from 97.43 % to 103.71 % in spiked cereal products. These findings highlight the potential of the developed bimodal aptasensor as a novel tool for the rapid, accurate, and cost-effective detection of ZEN in cereal products, contributing to improved food safety monitoring.