Y-shaped DNA aptamer-modified infrared dual-band metasurface sensor for high-performance fingerprint detection of...

Mycotoxins contaminating a wide range of food products consumed by humans, pose significant threats to human health. Among these, ochratoxin A and fumonisin B1 are two of the most prevalent mycotoxins. The frequent co-occurrence of these toxins in food products, coupled with their additive or synergistic toxic effects, underscores the critical need for a sensitive and multiplexed detection method. In this study, we propose a dual-band infrared spectral sensor based on a metal-insulator-metal metasurface to enhance molecular detection sensitivity. The sensor integrates hexagonal and rectangular metasurface structures, enabling simultaneous resonance at multiple infrared wavelengths to cover the characteristic absorption bands of both mycotoxins. A Y-shaped DNA aptamer was synthesized and immobilized on the sensor surface, providing specific recognition and capture of fumonisin B1 and ochratoxin A. Experimental results demonstrated high sensitivity, with detection sensitivities of 2.051 % (ng/mL)^-1 for fumonisin B1 and 2.705 % (ng/mL)^-1 for ochratoxin A, and detection limits of 0.148 ng/mL and 0.202 ng/mL, respectively. Spiking recovery tests in beer and black tea confirmed the accuracy and reliability in real-sample analysis. This work advances infrared spectroscopy-based mycotoxin detection, offering a non-destructive, label-free, and highly sensitive sensing platform for food safety and public health applications.