Ph-CN-based electrochemiluminescence detection of AFB₁ in peanut and peanut products

Aflatoxin B₁ (AFB₁) is the most dangerous mycotoxin found so far; it can cause serious pollution and economic losses to agricultural products, and also cause harm to human health due to its toxicity. Therefore, it is essential to realize improved detection of AFB₁ with high sensitivity and excellent selectivity. Herein, phenyl carbon nitride (Ph-CN) was prepared by thermal polymerization. Compared with carbon nitride (CN), Ph-CN has higher electrochemiluminescence (ECL) intensity and stability. In a lower concentration of potassium persulfate (K₂S₂O₈) solution, Ph-CN can show high ECL intensity and stability, while avoiding the oxidative damage caused by high concentration of co-reactive reagents on biomolecules. An ECL biosensor platform based on Ph-CN was proposed to monitor AFB₁ in peanut and its products. In the presence of the target AFB₁, the aptamer binds to the target and reduces the ECL signal. The aptasensor can sensitively detect AFB₁ in the linear range 100 fg mL^-1-100 ng mL^-1, with detection limits as low as 25 fg mL^-1. The assay showed good specificity for AFB1 due to the application of AFB1 aptamers, which makes it a potential application prospect in complex solutions.