A stimuli-responsive colorimetric aptasensor based on the DNA hydrogel-coated MOF for fumonisin B determination in food samples.

Fumonisin B (FB), the most occurring fumonisin, is capable of disrupting sphingolipid metabolism and poses a serious threat to human and animal health. The high incidence and toxicity of FB have created an urgent need for alternative quantitative determination strategies. Herein, a colorimetric aptasensor was developed by combining the catalytical metal-organic frameworks with the polyacrylamide-DNA hydrogel. The porphyrin-based MOF provided the aptasensor with robust peroxidase-like activity while maintaining good stability. Concurrently, the polyacrylamide-DNA hydrogel constructed via strand-induced hybridization chain reaction (HCR) endowed the aptasensor with outstanding stimuli-responsiveness towards FB molecules. The developed aptasensor demonstrated remarkable selectivity and ease of use for assays conducted in solution and food samples. It also exhibited superior analytical performance with a linear range of 0.05-100 ng mL and a limit of detection (LOD) of 0.024 ng mL. The strategy could serve as a model to develop diverse stimuli-responsive aptasensors targeting hazards in food safety.