Development and comparison of electrochemical peptide biosensor based on AuNPs@f-CNFs or AuNPs/rGO-COOH-Atp for detection of zearalenone in cereals.

Two simple and sensitive electrochemical biosensors have been developed and compared based on a specific peptide for detection of zearalenone (ZEN) in cereals. The two nanomaterials AuNPs@f-CNFs and AuNPs/rGO-COOH-Atp were introduced to enhance electron transfer and mass transfer, thereby improving the electrochemical signal. Compared with the two developed methods, the peptide biosensor with AuNPs@f-CNFs had higher sensitivity, better accuracy and excellent stability. Under the optimal conditions, the limit of detection (S/N = 3) was 0.79 pg/mL and the linear range was 0.02-12 ng/mL. It showed good accuracy with 84.0 %-101.6 % recovery and agreement with the commercial kit in cereals. Furthermore, the peptide biosensor with AuNPs@f-CNFs still remained at 90.2 % of the initial current response after 20 days of storage, while that with AuNPs/rGO-COOH-Atp showed a significant decrease in current response after the seventh day. It was found that the method could be applied for the detection of ZEN residue in cereals.