title: Differentiation and classification of bacteria using vancomycin functionalized silver nanorods array based surface-enhanced Raman spectroscopy and chemometric analysis.
abstract: Twenty seven different bacteria isolates from 12 species were analyzed using intrinsic surface-enhanced Raman scattering (SERS) spectra with recently developed vancomycin coated silver nanorod (VAN AgNR) substrates. The VAN AgNR substrates could generate reproducible SERS spectra of the bacteria with little to no interference from the environment or bacterial by-products as compared to the pristine substrates. By taking advantage of the structural composition of the cellular wall which varies from species to species, the differentiation of bacterial species is demonstrated by using chemometric analyses on those spectra. A second chemometric analysis step within the species cluster is able to differentiate serotypes and strains. The spectral features used for serotype differentiation arises from the surface proteins, while Raman peaks from adenine dominate the differentiation of strains. In addition, due to the intrinsic structural differences in the cell walls, the SERS spectra can distinguish Gram-positive from Gram-negative bacteria with high sensitivity and specificity, as well as 100% accuracy on predicting test samples. Our results provide important insights for using SERS as a bacterial diagnostic tool and further guide the design of a SERS-based detection platform.
authors.affiliation: Department of Food Science and Technology, University of Georgia, Athens, GA 30602, United States; Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602, United States.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Food Science and Technology, University of Georgia, Athens, GA 30602, United States.
authors.forename: Yao-Wen
authors.initials: YW
authors.lastname: Huang
authors.affiliation: USDA Agricultural Research Service, Russell Research Center, Athens, GA 30605, United States.
authors.forename: Bosoon
authors.initials: B
authors.lastname: Park
authors.affiliation: Department of Infectious Diseases, University of Georgia, Athens, GA 30602, United States.
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Tripp
authors.affiliation: Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602, United States; Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602, United States. Electronic address: zhaoy@physast.uga.edu.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D001419:Bacteria / Q000737:chemistry* / Q000145:classification* / Q000302:isolation & purification; D004396:Coloring Agents / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D014640:Vancomycin / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D012834:Silver; D014640:Vancomycin
keywords: Bacteria detection; Chemometric analysis; Silver nanorods; Surface enhanced Raman scattering; Vancomycin