A fluorescence based immunochromatographic sensor for monitoring chlorpheniramine and its comparison with a gold nanoparticle-based lateral-flow strip

Abstract

Chlorpheniramine (CPM) is an illegal additive found in herbal teas and health foods, and its excessive intake can cause health problems. In this study, a CPM monoclonal antibody (mAb) was developed based on a new type of hapten. The mAb was found to belong to the IgG2b subclass and showed high sensitivity and specificity when used in ELISA, with a half-maximal inhibitory concentration (IC₅₀) of 0.98 ng mL⁻¹ and cross-reactivity (CR) values below 1.8% when compared to antiallergic drugs. Based on the mAb produced, a fluorescent microsphere-based immunochromatographic strip assay (FM-ICS) and a gold nanoparticle-based immunochromatographic strip assay (GNP-ICS) were developed for the rapid and sensitive detection of CPM in herbal tea samples. Under optimal conditions, the cut-off values for the FM-ICS and GNP-ICS were 10 ng mL⁻¹ and 100 ng mL⁻¹, respectively, in herbal tea samples. The FM-ICS exhibited a higher sensitivity than GNP-ICS, but both could produce results within 15 min. In addition, a variety of high-throughput rapid immunoassay formats could be implemented based on this mAb for use as a convenient and reliable tool for the determination of CPM exposure in foods and the environment.