Resonant Raman and surface-enhanced Raman spectroscopies for detecting viruses and antibiotic-resistant bacteria

The development of point-of-care test systems for pathogen detection is of high interest due to recent viral pandemics and increasing threat of multiple antibiotic resistance of bacteria. Existing rapid diagnostics methods are mainly represented by molecular diagnostics, such as PCR methods, and immunochromatographic test strips. The first group exhibits a low limit of detection, typically 100-1000 genomes/mL. However, these methods require several hours for analysis and highly equipped laboratory. Immunochromato-graphic test strips, on the contrary, are easy to use and provide results within 10-15 minutes, but they are able to determine the target within a narrow concentration range and have a high detection limit of up to 10⁵ pathogens/mL. New methods are emerging to meet the requirements for rapid and specific detection. Surface-enhanced Raman spectroscopy (SERS) is one of the most sensitive methods. It can significantly improve the sensitivity of biosensors. The most exciting results in pathogen detection have been achieved using resonant surface-enhanced Raman spectroscopy which provides determination of several pathogens in the sample. This chapter summarizes recent achievements in the field.