The investigation of laser-induced breakdown spectroscopy for detection of biological contaminants on surfaces

The potential utility of laser-induced breakdown spectroscopy (LIBS) as a means to detect biological contaminants on painted surfaces is investigated. LIBS offers an in-situ capability for instantaneous qualitative analysis of the elemental composition of materials. The use of LIBS for detection of biologicals and the apparatus that are assembled are discussed. The apparatus are assembled in the manner in which samples of bare copper and painted substrates onto which thin layers of bacterial spores, pollen, molds, and contaminants were prepared. A chemometric analysis methodology consisting of spectral preprocessing, principal components analysis, linear discriminant analysis, and hierarchical cluster analysis yields an automated classification tool. LIBS spectra of contaminant layers over a complex substrate contain the information on the basis of which their biological content can be discerned.