Visible and eco‐friendly immunoassays for the detection of cyclopiazonic acid in maize and rice.

Cyclopiazonic acid (CPA) is an indole‐tetramine mycotoxin commonly produced by Penicillium and Aspergillus and is widely found in agricultural products, fermented food, and feed. Food contaminated with CPA poses a substantial health risk to consumers. Therefore, eco‐friendly immunoassays, including an indirect competitive enzyme‐linked immunosorbent assay (ic‐ELISA) and a lateral flow immunochromatographic strip (LFICS), were developed to monitor CPA in maize and rice samples. For this purpose, a monoclonal antibody (3H12) posed highly resistant to pH (5.6 to 9.6) and ethanol (≤50%) was generated by mouse immunization. Negative maize and rice samples or samples spiked with CPA were extracted with ethanol/0.01 M sodium borate buffer (4/1, v/v, pH 8.4). For ic–ELISA analysis, the limits of detection (LODs) were 0.48 and 0.28 ng/g for maize and rice samples, respectively. The recovery for spiked maize was 76.9% to 83.5% with the highest variable coefficient (CVmax) being 9.32%. For spiked rice, the recovery was 85.3% to 105.1% with a CVmax of 8.56%. For LFICS analysis, the visible LODs were 2.5 and 1 ng/g and cutoff values were 5 and 2.5 ng/g for maize and rice samples, respectively. The LFICS method gave results within 5 to 10 min, providing an auxiliary analytical tool for the rapid, sensitive, and portable screening of the massive samples onsite. [ABSTRACT FROM AUTHOR]