N/O co-doping porous biomass carbon constructed electrochemical sensor for universal and sensitive detection to mycotoxins.

Mycotoxin contamination poses a great threat to food safety and human health. Thus, universal and sensitive detection of mycotoxins is urgently needed. Herein, N/O co-doped porous biomass carbon was synthesized from rice straw as a novel electrode modification material for fabricating an electrochemical sensor for mycotoxin detection. The fabricated sensor exhibited excellent universality in the detection of aflatoxin B1, aflatoxin G1, aflatoxin G2, aflatoxin M1, zearalenone, and deoxynivalenol. The limits of detection were ca. 0.5689, 0.0504, 0.0274, 0.6141, 0.0781, and 0.0512 fg·mL, respectively. The dynamic linear range was spanned from 0.001 to 1000 pg·mL. The biomass carbon-based electrochemical sensor also demonstrated accurate and rapid performance in detecting mycotoxins in real samples, with all recoveries near 100 %. Density functional theory calculation confirmed that the adsorption of mycotoxins by porous carbon changed the charge distribution of the electrode surface, which is the potential working mechanism of the designed electrochemical sensor for high sensitivity mycotoxin detection. The results indicated that the high sensitivity of the fabricated electrochemical sensor makes it suitable for the fast and accurate detection of mycotoxins in grain and feed products.