A comb-shaped microfluidic aptasensor for rapid and sensitive on-site simultaneous detection of aflatoxin B1 and...

Mycotoxins are widely found as co-contaminants in agricultural products and their derivatives. However, on-site monitoring of multiple mycotoxins remains a significant challenge. We developed an electrochemical aptasensor integrating microelectrodes and microfluidics for simultaneous aflatoxin B1 (AFB1) and deoxynivalenol (DON) detection. Its sensing interface had dual working electrodes modified with two specific aptamers, sharing a counter and a reference electrode. The microfluidic chip's comb-shaped structure enhanced aptamer-target binding. Using a buffer with redox probes for electrochemical detection, we achieve label-free quantitative detection of both toxins within 20 min. The sensor had detection limits of 7.74 pg/mL for AFB1 and 0.172 ng/mL for DON, with linear detection ranges of 0.03-300 ng/mL and 0.3-3000 ng/mL respectively. It exhibited excellent specificity, repeatability and stability. In summary, this electrochemical aptasensor enables rapid and sensitive on-site detection of AFB1 and DON, safeguarding food safety during grain storage for early monitoring and prevention.