Raman-based detection of bacteria using silver nanoparticles conjugated with antibodies.
Surface enhanced Raman scattering (SERS) has been used to detect bacteria captured by polyclonal antibodies sorbed onto protein-A-modified silver nanoparticles. The selectivity and discrimination of the technique were assured by using a specific antibody to the model bacterium, Escherichia coli. As the SERS enhancement mechanism depends upon the metal surface proximity, 8 nm was considered as the optimum distance between the bacterium and the nanoparticle surface. Spectral reproducibility was verified using Principal Components Analysis to differentiate the clusters corresponding to the biomolecules and/or bacteria sorbed onto nanoparticles. Compared to the normal Raman spectrum, the SERS technique resulted in an intensity enhancement of over 20-fold.
Naja
Ghinwa
G
Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, Canada H4P 2R2. ghinwa.naja@nrc.ca
Bouvrette
Pierre
P
Hrapovic
Sabahudin
S
Luong
John H T
JH
D000818:Animals; D000907:Antibodies, Bacterial; D001422:Bacterial Adhesion; D004926:Escherichia coli / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D025341:Principal Component Analysis; D011817:Rabbits; D012680:Sensitivity and Specificity; D012834:Silver; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013205:Staphylococcal Protein A
D000907:Antibodies, Bacterial; D013205:Staphylococcal Protein A; D012834:Silver