옥수수 분말 중 오크라톡신 A의 신속 검출을 위한 단클론항체 기반 측방유동면역분석법 개발

초록

Ochratoxin A (OTA) is a small-molecule mycotoxin that can contaminate cereals during storage, highlighting the need for rapid screening. In this study, a monoclonal antibody-based competitive lateral flow immunoassay (LFIA) was developed to detect OTA in corn flour. Because small molecules such as mycotoxins generally cannot simultaneously bind to the two antibodies required for conventional sandwich immunoassays, a competitive format was used. In this assay, free OTA in the sample competed with OTA-bovine serum albumin (OTA-BSA) immobilized on the test spot for binding to an anti OTA monoclonal antibody (mAb) conjugated to gold nanoparticles (GNPs). Key assay parameters, including the pH and amount of antibody used to prepare the GNP-OTA mAb conjugate, OTA-BSA concentration, amount of GNP-OTA mAb conjugate, extraction solvent composition, and volume of sample extract applied to the strip, were optimized. Under the optimized conditions, OTA standards prepared in 30% methanol/PBS produced a concentration-dependent decrease in test-spot intensity within 15 min, with a visual detection limit of 5 ng/mL. OTA-spiked corn flour samples showed a reduction in test-spot intensity at 5 µg/kg. No appreciable inhibition was observed with fumonisin B1, aflatoxin B1, zearalenone, or 3-acetyldeoxynivalenol under the test conditions, indicating good specificity for OTA. The developed LFIA provides a simple, portable, and instrument-free method for rapid on-site screening of OTA in corn flour.

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