title: Activation of nanoparticles by biosorption for E. coli detection in milk and apple juice.
abstract: Two types of silver nanoparticles were activated by specific sorption of biomolecules for the detection of Escherichia coli. The capture of this bacterium was performed using polyclonal antibodies (anti-E. coli) biosorbed onto nanospheres or nanorice through a protein-A layer. The bacterial detection was achieved using surface enhancement Raman scattering in order to compare the performance of these two nanoparticles. The activated silver nanospheres showed a better performance mainly due to the dimension of these nanoparticles. The detection limit has been established using the automated Raman mapping system. The technique was capable of detecting 10(3) cells/mL in milk and apple juice without any pre-enrichment. With an overall assay time less than 1 h, the process could be easily adapted to detect other pathogens by selecting the pertinent antibody. Furthermore, PCR was used for the DNA verification to assess whether the selected bacterial strain was identical before and after detection.
authors: Biotechnology Research Institute, National Research Council Canada, H4P 2R2 Montreal, Quebec, Canada. mnaja@evergladesfoundation.org
authors: Ghinwa
authors: G
authors: Naja
authors: Pierre
authors: P
authors: Bouvrette
authors: Julie
authors: J
authors: Champagne
authors: Roland
authors: R
authors: Brousseau
authors: John H T
authors: JH
authors: Luong
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000737:chemistry / Q000276:immunology*; D004926:Escherichia coli / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification* / Q000648:ultrastructure; D027845:Malus / Q000382:microbiology*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008892:Milk / Q000382:microbiology*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013059:Spectrum Analysis, Raman
chemical_list: D000907:Antibodies, Bacterial