Standoff laser induced fluorescence of living and inactivated bacteria

Abstract

Biological hazards, such as bacteria, represent a non-assessable threat in case of an accident or a terroristic attack. Rapid detection and highly sensitive identification of released, suspicious substances at low false alarm rates are challenging requirements which one single technology cannot cope with. It has been shown that standoff detection using laser-induced fluorescence (LIF) can provide information on the class of bioorganic substances in real-time1. In combination with traditional, highly sensitive, but non-standoff methods, the time for identification of the threat can be optimized. This work is aimed at the selectivity of LIF technology for different bacterial strains. A second important aspect examines how to deal with inactivated bacteria and how their fluorescence signature changes after deactivation. LIF spectra of closely and more distantly related bacterial strains are presented as well as spectra of bacteria treated by different inactivation methods.