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

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Ding S., Hu H., Yue X., Feng K., Gao X., Dong Q., ...More

JOURNAL OF DAIRY SCIENCE, vol.105, no.4, pp.2895-2907, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 105 Issue: 4
  • Publication Date: 2022
  • Doi Number: 10.3168/jds.2021-21229
  • Journal Name: JOURNAL OF DAIRY SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Periodicals Index Online, Agricultural & Environmental Science Database, Analytical Abstracts, BIOSIS, Business Source Elite, Business Source Premier, CAB Abstracts, Chemical Abstracts Core, EMBASE, Environment Index, Food Science & Technology Abstracts, MEDLINE, Veterinary Science Database, DIALNET
  • Page Numbers: pp.2895-2907
  • Keywords: quantum dots, milk, Salmonella, fluorescence, AMPLIFICATION METHOD, PATHOGENIC BACTERIA, AFLATOXIN B-1, ASSAY, NANOPARTICLES, IMMUNOASSAY, SEPARATION, CONJUGATE, SYSTEM
  • Gazi University Affiliated: Yes

Abstract

Salmonella, as a common foodborne pathogen in dairy products, poses a great threat to human health. We studied a new detection method based on quantum dots (QD). A fluorescent biosensor with multiple fluorescent signal amplification based on a streptavidin (SA) biotin system and the polyamino linear polymer poly-l-lysine (PLL) were established to detect Salmonella in milk. First, Salmonella was captured on a black 96-well plate with paired Salmonella mAb to form a double-antibody sandwich. Second, SA was immobilized on biotin -modified mAb by SA-biotin specific bond. Then, the biotin modified polylysine (BT-PLL) was bound on SA and specifically bonded again through the SA-biotin system. Finally, water-soluble CdSe/ZnS QD-labeled SA was added to a black 96-well plate for covalent coupling with BT-PLL. The fluorescent signal was amplified in a dendritic manner by the layer-by-layer overlap of SA and biotin and the covalent coupling of biotinylated PLL. Under optimal conditions, the detection limit was 4.9 x 10(3) cfu/mL in PBS. The detection limit was 10 times better than that of the conventional sandwich ELISA. In addition, the proposed biosensor was well specific and could be used for detecting Salmonella in milk samples.