Detecting presence of live and dead pathogenic organisms in water and the water solutions by laser spectroscopy

Presented is a new method for the recognition of live or dead pathogens in water. This method is based on the diagnostics of non-linear effects that comprise two phenomena: an induced luminescence of DNA under the influence of laser radiation, and a stimulated Brillouin scattering (SBS). The following model parameters were selected for the identification: the peak positions of spectral lines corresponding to pathogens and the difference between two wavelengths corresponding, respectively, to a laser mode maximum, and to a peak of the spectral line of a pathogen. A large volume of experimental data has been obtained and statistical analysis using Student's test was carried out in order to determine the probability of the detection of spectra. The dynamics of the spectra of direct dispersion have been studied for a number of bacteria. Based on these results, the method and the device were developed. That device was tested in a water pipe line. In addition, we have studied the dynamics of changes in the spectra for solutions containing live bacteria and dead cells. (letter)