Development of an immunochromatographic strip assay for three major capsaicinoids based on an ultrasensitive monoclonal antibody

Abstract

The problem of waste oil is a food safety issue that requires urgent resolution. In this study, a novel hapten was designed for the rapid detection of capsaicinoids, a marker of waste oil, and a monoclonal antibody (MAb) 5D7 was generated that is specific for three major capsaicinoids: capsaicin (CPC), dihydrocapsaicin (DCPC), and Nvanillylnonanamide (N-V). The half maximal inhibitory concentrations of MAb 5D7 for CPC, DCPC, and N-V were 1.12, 0.8, and 0.87 ng/mL, respectively. An immunochromatographic strip test based on MAb 5D7 was established for these three capsaicinoids, with visual inspection limits of <1.0 ng/mL, which satisfies the requirement for the rapid on-site inspection of waste oil.

Hydrophobic Moiety of Capsaicinoids Haptens Enhancing Antibody Performance in Immunoassay: Evidence from Computational Chemistry and Molecular Recognition

“…The antisera results provide strong evidence that the previous reported hapten design strategy can lead to a decrease in the specificity of the resulting antibody to CPCs and thus result in false positive detection of the developed immunoassay. 16,17 In conclusion, the novel hapten1−4 proposed in this study were superior in producing antibodies with high affinity and specificity to CPCs than hapten5−8, which confirmed our hypothesis. To further confirm the key factors that affect the ability of haptens to induce antibody responses, the physicochemical descriptors of hapten1−8 such as LogP, V m /surface, and so on were extracted.…”

“…By calculating the mean concentration of 20 blank oil samples plus three times the standard deviation, the limits of detection (LODs) of the icELISA for four CPCs (CPC, DCPC, NDCPC, and N-V) were determined as 0.73, 0.77, 1.46, and 3.29 μg/kg in oil, respectively, which are far below the reported LODs for CPCs by other reports (Table S1). 16,17,26 The accuracy and precision of the developed icELISA were evaluated by measuring the recovery and coefficient of variation (CV) of spiked oil samples. CPC-negative oil samples were spiked with four individual CPCs (CPC, DCPC, NDCPC, and N-V) at three different concentrations (Table 2).…”

“…Adulteration of edible oil with refined waste oil has been one of the most concerning problems of current food quality control in developing countries . Thus, there is a high demand for rapid, sensitive, and specific detection of CPCs to ensure the quality of edible oils. − At present, some immunoassays for the determination of CPCs have been described. − In these studies, with the consideration of producing antibodies that can recognize total CPCs, nearly all the designed haptens were biased toward exposing the common vanillyl amide moiety rather than the alkane chain moiety of CPCs. However, the obtained antibodies showed low affinities to CPCs with the half inhibition (IC 50 ) varying from 1.12 to 160,000 ng/mL, which are insufficient to develop highly sensitive immunoassays for CPCs (Table S1).…”

“…However, the obtained antibodies showed low affinities to CPCs with the half inhibition (IC 50 ) varying from 1.12 to 160,000 ng/mL, which are insufficient to develop highly sensitive immunoassays for CPCs (Table S1). , Perhaps even worse, the antibodies induced by these haptens provided inaccurate recognition ability, that is, low specificity, which inevitably recognize not only CPCs but also other analogues that contain a vanillyl amide structure simultaneously, for example, guaiacol, 4-methylguaiacol, 4-ethylguaiacol, and so on (Table ). These analogues are naturally present in several kinds of vegetable oils or used as food additives that may coexist with CPCs during waste oil treatment, which can result in false positive results. , Clearly, to further improve the detection performance of immunoassays to meet the practical detection requirements, a more efficient hapten design strategy needs to be proposed to produce antibodies with high affinity and specificity to CPCs.…”

Simultaneous and rapid detection of carbofuran and 3-hydroxy-carbofuran in water samples and pesticide preparations using lateral-flow immunochromatographic assay

“…Strip-based immunoassays are specific, sensitive and sample pre-treatment simplified and could obtain the result within 5 min. With the advantage of detecting structural analogues, broad-specific antibodies could be used in the immunochromatography assay to improve the efficiency in practice (Cliquet, Goddeeris, Okerman, & Cox, 2007;Franek, Diblikova, Cernoch, Vass, & Hruska, 2006;Guo et al, 2009;Jiang, He, Gong, Gao, & Xu, 2019;Jin, Guo, Wang, Wu, & Zhu, 2009;Lan et al, 2019;Pagkali et al, 2018;Sun et al, 2018).…”