A fluorescent biosensor based on quantum dot–labeled streptavidin and poly-l-lysine for the rapid detection of Salmonella in milk

• DOI: 10.3168/jds.2021-21229
• Publication Date: 2022-02-16T07:37:20Z
• Authors: Shuangyan Ding; Hailiang Hu; Xianglin Yue; Kaiwen Feng; Xiaoyu Gao; Qiuling Dong; Mingqi Yang; Ugur Tamer; Ganhui Huang; Jinsheng Zhang
• Keywords: Streptavidin

Salmonella, as a common foodborne pathogen in dairy products, poses great threat to human health. We studied new detection method based on quantum dots (QD). A fluorescent biosensor with multiple signal amplification streptavidin (SA) biotin system and the polyamino linear polymer poly-l-lysine (PLL) were established detect Salmonella milk. First, was captured black 96-well plate paired mAb form double-antibody sandwich. Second, SA immobilized biotin-modified by SA-biotin specific bond. Then, polylysine (BT-PLL) bound specifically bonded again through system. Finally, water-soluble CdSe/ZnS QD-labeled added for covalent coupling BT-PLL. The amplified dendritic manner layer-by-layer overlap of biotinylated PLL. Under optimal conditions, limit 4.9 × 103 cfu/mL PBS. 10 times better than that conventional sandwich ELISA. In addition, proposed well could be used detecting milk samples.