Identification of bacteria using surface-enhanced Raman spectroscopy

Introduction Surface enhanced Raman scattering (SERS) spectroscopy can be efficiently employed for the label-free detection and discrimination of different bacteria. The fingerprint-quality bacterial spectra allow... [ view full abstract ]

Introduction

Surface enhanced Raman scattering (SERS) spectroscopy can be efficiently employed for the label-free detection and discrimination of different bacteria. The fingerprint-quality bacterial spectra allow identification of bacteria at the genus, the species, and even at the intraspecies level.

Methods

SERS spectra were acquired with BWS415 spectrometer (BWTEC, Germany). The specimen was put on the XYZ-stage, while position of laser focus was controlled by USB microscope Mikmed-2000R (Micromed, Russia). SERS spectra of bacteria were registered using drop-casted nanoparticle-based substrates either with or without the oxidative treatment with hydrogen peroxide.

Results

SERS spectra were registered for the number of clinically relevant bacterial species. Fluorescence background subtraction, filtering, normalizing and automated peak recognition were performed by means of home-developed GNU/Octave subroutines. Recognized peaks were assembled into the matrix, and processed by principal component analysis (PCA).

Discussion

Bacterial SERS spectra were significantly amplified while registering with oxidative treatment. The discriminating spectral performance was reduced, but was still high enough for the reliable identification of bacteria.

This work was funded by the Russian Science Foundation (project 17-79-10489).