Advanced dual-signal point-of-care testing platform for sensitive T-2 toxin detection: Integrating copper-based conductive MOF with target-responsive DNA hydrogel

In this study, we present the innovative design and comprehensive evaluation of a novel point-of-care testing (POCT) methodology for the rapid and accurate detection of T-2 toxin, a potent mycotoxin with significant implications for food safety and human health. The cornerstone of this approach lies in the integration of a copper-based conductive metal-organic framework (Cu 3 (HHTP) 2 ) with a target-responsive DNA hydrogel system, creating a dual-signal readout mechanism that significantly enhances detection sensitivity and specificity. Specifically, the hydrogel covers the material's surface metal active sites, which become exposed upon target addition due to hydrogel collapse. The released Cu 3 (HHTP) 2 can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine, resulting in a colorimetric and temperature change in the solution. This dual-mode detection strategy enables both qualitative assessment through direct visual inspection of color change and quantitative analysis by monitoring the solution temperature variation post laser irradiation with a thermometer. Under the optimized conditions, the detection system demonstrates a wide range spanning from 5 to 200 ng/mL, with a detection limit of 1.67 ng/mL. This method has been successfully demonstrated through the analysis of real-world samples, yielding encouraging results that underscore its reliability and effectiveness. The proposed dual-signal approach boasts advantages such as straightforward operational procedures, unambiguous signal outputs, and robust practicality, making it an attractive option for mycotoxin detection in resource-constrained settings and developing regions.