Laser induced fluorescence technologies applied for the standoff detection of bioaerosols

Abstract

The instantaneous detection of hazardous bioaerosols, spread intentionally or accidentally, is important to be able to react with countermeasures and prevent the further spread of pathogens. Laser induced fluorescence (LIF) technology is a suitable method for instant detection and localization of bacterial aerosol clouds from longer distances. LIF allows for the standoff differentiation of bacteria from other substances in the environment like pollen, oils or chemicals. After detection, samples of bacteria can be collected and subsequently analyzed in a laboratory by other methods like DNA sequencing or polymerase chain reaction assays for identification. A LIF detection system for bioaerosol detection, which records spectrally and time resolved fluorescence signals excited by two consecutive laser pulses with different wavelengths at 266 nm and 355 nm, is evaluated on aerosols. The setup enables fast data acquisition and provides a complete dataset in less than a few milliseconds at repetition rates of 100 Hz. The generation of biological test aerosols of different concentrations for the evaluation of detection systems and the detection of these aerosols at distances above 20 m is shown. Bacteria can be distinguished from other substances.