Fluorescence detection of biological aerosols

Summary form only given. The application of two-dimensional spectral analysis to microbes and other biological particles suspended in the atmosphere requires laser excitation in the ultraviolet spectral region. Much of the previous study on spectral characterization has been restricted to bulk samples of biological materials. In this study, a KrF excimer laser at 248 nm was used to carefully determine absolute fluorescent cross sections, while a tripled Cr:LiSAF laser, tunable from 265 to 290 nm, was used to obtain excitation-emission matrix (EEM) profiles. The higher intensity of tunable laser sources is critical to investigating biological material in aerosol form.