Research progress on ratiometric electrochemical sensing of mycotoxins

Mycotoxins widely exist in moldy agricultural products, which have the effects of teratogenicity, nephrotoxicity and carcinogenicity. Mycotoxin contamination has been listed as the main source of foodborne diseases by the World Health Organization. Current food security issues have highlighted the demand to have sensitive, rapid, and reliable platforms for mycotoxin detection. Electrochemical method with the merits of convenient instrument and rapid response has been widely applied to detect mycotoxins in agricultural products. By coupling the advantages of electrochemical method with ratiometric strategies, ratiometric electrochemical sensing can further enhance the robustness and accuracy of electrochemical sensors in complex conditions. This review highlights the recent progress (2019–2022) on ratiometric electrochemical sensors for mycotoxins detection from 5 aspects: direct sensing, antibody-based sensing, DNA-based sensing, aptamer-based sensing, and molecularly imprinted polymer (MIP)-based sensing. Their signal generation strategies and sensing mechanisms are described in detail, and the recognition elements, sensing materials and analytical performances in different sensing modes are compared, along with the advantages and disadvantages of different sensing modes. Finally, a comprehensive discussion is provided on the challenges and prospects of ratiometric electrochemical sensors for mycotoxins.