title: Fast, reagentless and reliable screening of "white powders" during the bioterrorism hoaxes.
abstract: The classification of dry powder samples is an important step in managing the consequences of terrorist incidents. Fluorescence decays of these samples (vegetative bacteria, bacterial endospores, fungi, albumins and several flours) were measured with stroboscopic technique using an EasyLife LS system PTI. Three pulsed nanosecond LED sources, generating 280, 340 and 460nm were employed for samples excitation. The usefulness of a new 460nm light source for fluorescence measurements of dry microbial cells has been demonstrated. The principal component analysis (PCA) and hierarchical cluster analysis (HCA) have been used for classification of dry biological samples. It showed that the single excitation wavelength was not sufficient for differentiation of biological samples of diverse origin. However, merging fluorescence decays from two or three excitation wavelengths allowed classification of these samples. An experimental setup allowing the practical implementation of this method for the real time fluorescence decay measurement was designed. It consisted of the LED emitting nanosecond pulses at 280nm and two fast photomultiplier tubes (PMTs) for signal detection in two fluorescence bands simultaneously. The positive results of the dry powder samples measurements confirmed that the fluorescence decay-based technique could be a useful tool for fast classification of the suspected "white powders" performed by the first responders.
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
authors.forename: Maksymilian
authors.initials: M
authors.lastname: Włodarski
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland. Electronic address: mkaliszewski@wat.edu.pl.
authors.forename: Miron
authors.initials: M
authors.lastname: Kaliszewski
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland; Department of Microbiology, Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163 Warsaw, Poland.
authors.forename: Elżbieta Anna
authors.initials: EA
authors.lastname: Trafny
authors.affiliation: Department of Microbiology, Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163 Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Szpakowska
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland; Department of Microbiology, Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163 Warsaw, Poland.
authors.forename: Rafał
authors.initials: R
authors.lastname: Lewandowski
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Bombalska
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Kwaśny
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kopczyński
authors.affiliation: Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Mularczyk-Oliwa
mesh_terms: D023482:Bioterrorism; D016000:Cluster Analysis; D008192:Deception; D005453:Fluorescence; D005658:Fungi / Q000502:physiology; D006801:Humans; D011208:Powders; D025341:Principal Component Analysis; D013171:Spores, Bacterial / Q000502:physiology; D049489:Stroboscopy
chemical_list: D011208:Powders
keywords: Fluorescence lifetime; Hierarchical cluster analysis (HCA); Microorganisms fluorescence decay; Principal component analysis (PCA); UV LED stroboscopic technique; White powders fluorescence analysis