Rapid Quantum Dot Nanobead-mAb Probe-Based Immunochromatographic Assay for Antibody Monitoring of Trichinella spiralis Infection

Abstract

Purpose: Sensitive and selective point-of-care biosensor is an urgent pursuit of serological antibody detection to control parasite pathogen. For specific, quantitative and on-site screening of Trichinella spiralis infection in livestock, a quantum dot nanobead-monoclonal antibody (QB-mAb) probe-based immunochromatographic assay (ICA) was developed by introducing a competitive sandwich strategy (QB-CICA). Methods: In the QB-CICA, QB-mAb probes competed with serum antibody for a particular epitope, followed by immunocomplexes binding to capture antibody on the test line. With the accumulation of target antibody, captured probes served as signal elements for fluorescent readout in a "turn off" mode, along with the fluorescence gradually weakened. The sensitivity and standard calibration curve of the QB-CICA were quantified using swine sera as negative control (n = 200) and artificial infected swine sera (n = 80) compared with a commercial ELISA kit. Besides, Trichinella spiralis-antibody targeting test ability of the QB-CICA, instead of other parasites or viruses antibodies (n = 10), was evaluated. Results: The QB-CICA exhibited a good linear range, a low detection limit of 189.92 ng mL −1 and 100% selectivity that was higher than commercial ELISA kit (90%), as well as the same serological positive rate (100%) with commercial ELISA kit in different infection dose models. Conclusion:Taking advantage of its simplicity, short response time (25 min), sensitivity and specificity, the proposed QB-CICA has potential applications for parasite-related antibody monitoring in food safety and clinical diagnosis fields.

Lateral flow immunoassay strips based on europium(III) chelate microparticle for the rapid and sensitive detection of Trichinella spiralis infection in whole blood samples of pigs

“…Traditional ICS methods employ the use of gold nanoparticles, quantum dots, or fluorescent microspheres ( Liang et al., 2017 ; Willen et al., 2018 ; Lee et al., 2019 ). These different ICS methods have previously been developed for the diagnosis of Trichinella infection, albeit using serum samples from pigs and in a laboratory setting ( Zhang et al., 2006 ; Fu et al., 2013 ; Xu et al., 2021 ). Europium(III) chelate microparticle (ECM) is a fluorescent microsphere-based ICS and has the advantages of sensitivity and specificity.…”