Electrochemical-colorimetric dual-mode detection of zearalenone based on restriction endonuclease-driven DNA walker system.

Zearalenone (ZEN) is a toxic metabolite produced mainly by strains of Fusarium spp. and is characterized by high toxicity and easy residue. Prolonged exposure to ZEN-contaminated grains can produce a range of toxic effects in the body and affect human health. In this study, an electrochemical and colorimetric dual-mode biosensor for ZEN detection was developed based on streptavidin-modified magnetic beads (SA-MBs) and the DNA walker. In this strategy, Apt/Walker could be used to specifically recognize ZEN and trigger two endonuclease-driven walker reactions, which resulted in the disruption and cleavage of orbital chains on SA-MBs and on the electrode surface. This ultimately led to dynamic changes in the colorimetric signal of the solution and the electrochemical signal on the electrode surface. The integration of target recognition with dual signal amplification and the reliability of dual mode detection were some of the advantages of the designed sensor. Under optimal conditions, the detection limits for both modes were 3.44 × 10 mol/L (colorimetry) and 3.39 × 10 mol/L (electrochemistry), respectively. At the same time, this dual-mode sensor had good specificity and recovery. It addressed the limitations of traditional detection methods and has broad potential in areas such as food safety.