Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
College of Animal Sciences, Yangtze University, Jingzhou, People's Republic of China.
Int J Nanomedicine. 2021 Mar 29;16:2477-2486. doi: 10.2147/IJN.S304845. eCollection 2021.
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 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).
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, -antibody targeting test ability of the QB-CICA, instead of other parasites or viruses antibodies (n = 10), was evaluated.
The QB-CICA exhibited a good linear range, a low detection limit of 189.92 ng mL 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.
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.
灵敏且选择性的即时生物传感器是寄生虫病原体血清抗体检测的迫切需求。为了在现场对牲畜感染进行特异性、定量和筛选，本研究通过引入竞争夹心策略（QB-CICA），开发了基于量子点纳米珠-单克隆抗体（QB-mAb）探针的免疫层析分析（ICA）。
在 QB-CICA 中，QB-mAb 探针与血清抗体竞争特定表位，然后免疫复合物与测试线上的捕获抗体结合。随着目标抗体的积累，捕获的探针作为荧光读出的信号元件，以“关闭”模式起作用，同时荧光逐渐减弱。使用猪血清作为阴性对照（n = 200）和人工感染猪血清（n = 80），与商业 ELISA 试剂盒相比，定量了 QB-CICA 的灵敏度和标准校准曲线。此外，评估了 QB-CICA 针对-β抗体的检测能力，而不是针对其他寄生虫或病毒抗体（n = 10）。
QB-CICA 表现出良好的线性范围、低检测限 189.92ng/mL 和 100%的选择性，优于商业 ELISA 试剂盒（90%），并且在不同感染剂量模型中与商业 ELISA 试剂盒具有相同的血清阳性率（100%）。
利用其简单、短的响应时间（25 分钟）、灵敏度和特异性，所提出的 QB-CICA 有可能应用于食品安全和临床诊断领域的寄生虫相关抗体监测。
