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. Issues involving the use of LIBS for detection of biologicals are discussed. The apparatus assembled for this work is described, as is 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 that was able to identify bacterial spores with a false positive rate of 1% and a false negative rate of 3%.