XÂY DỰNG QUY TRÌNH CHẾ TẠO QUE THỬ SẮC KÝ MIỄN DỊCH CẠNH TRANH PHÁT HIỆN OCHRATOXIN A TRONG CÀ PHÊ

Abstract

Objective: To develop a process for the competitive lateral flow immunochromatography assay (LFIA) strip for rapid detection of Ochratoxin A (OTA) in coffee. Methods: The study was conducted through laboratory experiments following an 8-step process, with each step involving the optimization of various parameters to enhance the sensitivity of the test strip. The product test strips are evaluated for the limit of detection, the stability, the specificity, cross-reactivity and from there, a test strip manufacturing process is developed. Results: The optimal size of the gold nanoparticles was determined to be 30 nm, which enhanced the sensitivity and generated clear color signals on the test strip. The optimal concentration of antibodies coated on the gold nanoparticles was 10 µg/ml. The optimal concentration of OTA-BSA applied on the test line was 1 mg/ml, which produced a strong and stable color signal, allowing clear distinction between positive and negative samples. The limit of detection (LOD) was 6 µg/L. The stability of the test strip was maintained for 6 months when stored at 4°C and 25°C. Conclusion: We have successfully developed a competitive lateral flow immunoassay strip for the detection of Ochratoxin A in coffee with the limit of detection (LOD): 6 µg/L, the specificity: 90%, and the stability for 6 months when stored at 4°C and 25°C.