A smartphone-coupled electrochemical biosensor based on DNA tetrahedral scaffolds for simultaneous quantification of AFB1 and OTA

This study developed a novel dual-functional portable electrochemical biosensor capable of simultaneous and sensitive detection of AFB 1 and OTA. The biosensor incorporates SPCE modified with gold nanoflowers, which not only enhances electrical conductivity and specific surface area of work electrode but also supports the stable immobilization of DNA tetrahedral probes. This biosensor utilizes ferrocene and methylene blue as distinct electrochemical signal reporters and enables specific and parallel recognition of AFB 1 and OTA in a single measurement, this strategy greatly improves its detection efficiency. Integrated with a portable electrochemical workstation and smartphone, this platform facilitates rapid, user-friendly, and real-time mycotoxin detection. Under optimized conditions, the biosensor exhibited wide linear detection ranges (0.05–250 ng/mL) and impressive detection limits of 2.8 pg/mL (AFB 1 ) for and 4.1 pg/mL (OTA). This work developed platform exhibits excellent stability and field applicability, providing a practical integrated solution for on-site screening of multiple mycotoxin in agricultural products.