Indirect competitive ELISA based on the prepared polyclonal antibody for highly sensitive detecting illegal additive 4-chloro-oxyphenisatin diacetate in weight loss food products

Abstract 4-chloro-oxyphenisatin diacetate (Cl-Bisatin-DA), frequently added illegally to weight loss foods, has been proven to exert severe health hazards, highlighting the crucial importance of developing a rapid and sensitive analytical method. In this work, the hapten, antigens, and polyclonal antibody of Cl-Bisatin-DA were prepared, and the highly sensitive indirect competitive ELISA (ic-ELISA) using the prepared polyclonal antibody was established for the detection of Cl-Bisatin-DA in weight loss food products. Under optimal conditions, the detection limit (IC15) and sensitivity (IC50) of the established ic-ELISA were 1.07 ng/mL and 27.67 ng/mL, respectively. The cross-reactivity values of ten non-target analogs were below 0.2%. The application evaluation results showed that the spiked recovery rates of Cl-Bisatin-DA in zero-calorie jelly, solid beverage, enzyme beverage, pressed candy, and fruit vinegar beverage ranged from 76.1% to 106.6%, which were consistent with the LC-MS analysis results. The developed ic-ELISA provides a novel potential tool for the rapid and highly sensitive detection of Cl-Bisatin-DA in weight loss food products.