Direct competitive immunoassay method for sensitive detection of the histamine in foods based on a MI-Cu-GMP nanozyme marker and molecularly imprinted biomimetic antibody

BACKGROUND Histamine may lead to low blood pressure, skin flushing and edema when it accumulates in large amounts in the body. Therefore, establishing sensitive methods for the detection of histamine in foods is extremely important to ensure food safety and human health. RESULTS The MI-Cu-GMP NPs (2-methylimidazole-copper-guanosine monophosphate nanozymes) with high laccase-like activity were synthesized. Using the prepared molecular imprinted membrane as biomimetic antibody and MI-Cu-GMP NPs as marker, a sensitive direct competitive biomimetic enzyme-linked immunoassay (BELISA) method for rapid detection of the histamine in foods was developed. Under optimal conditions, the limit of detection (LOD, IC 15 ) and sensitivity (IC 50 ) of the BELISA method for histamine was 0.05 mg L −1 and 1.22 mg L −1 , respectively. The liquor samples spiked with histamine was detected by the BELISA method with satisfactory recoveries ranging from 90.00% to 116.00%. Further, the level of histamine in three samples (cooking wine, rice vinegar and soy sauce) was tested by the BELISA and high-performance liquid chromatography (HPLC), with no significant difference found between the two methods. CONCLUSION Given the advantages, the established BELISA method is expected to provide practical guidance for the monitoring of histamine in food and provides a foundation for the detection of other food hazards. © 2024 Society of Chemical Industry.