Development of a rapid time-resolved fluorescence immunoassay for cannabidiol quantification in Cannabis sativa L

As a main cannabinoid of Cannabis sativa L., cannabidiol is widely found in cosmetics, vaping liquid, and food. This study aimed to develop a quantitative test strip based on time-resolved fluorescence immunoassay for onsite cannabidiol detection. A monoclonal antibody was prepared against a novel cannabidiol hapten-protein conjugate, with a half maximal effective concentration of 17.90 ng ml −1 and a detection limit of 2.66 ng ml −1 . Based on the monoclonal antibody, a test strip was constructed and validated for the detection of cannabidiol in the cannabis plant. The detection limit was 9.39 ng ml −1 and the detection range was 21.62–374.24 ng ml −1 . The monoclonal antibody proved high specificity as showing no cross-reactivity with nine common cannabinoids including delta-8-tetrahydrocannabinol, delta-9-tetrahydrocannabinol, cannabichromene, cannabigerol, cannabinol, cannabidivarin, cannabicyclol, cannabicitran, and cannabidiphorol. Spike/recovery test and analysis of real samples demonstrated that the test strip is an accurate, sensitive, and specific detection technique for cannabidiol identification in Cannabis . • A novel cannabidiol hapten was designed and synthesized, against which a highly specific monoclonal antibody was developed. • Time-resolved fluorescence immunoassay was applied to prepare lateral flow test strips for cannabidiol detection in hemp. • Cross-reactivity test suggested the test strips are highly specific for cannabidiol. • Spike/recovery test and a good correlation with the standardized HPLC method confirmed accuracy and repeatability of the test strips.