Real-time measurement of fluorescence spectra from single airborne biological particles

Improved real-time methods for characterizing airborne biological particles are needed. Here we review our efforts in developing techniques for measuring the laser-induced fluorescence (total and spectrally dispersed) of individual airborne particles, and describe our present system, which can measure fluorescence spectra of single micrometer-sized bioaerosol particles with good signal-to-noise ratios. We demonstrate the capability of this system by showing measured spectra of a variety of airborne particles generated in the laboratory from road dust, ammonium sulfate, Bacillus subtilis and other bacteria prepared under various conditions, allergens, cigarette smoke, and chicken-house dust. These spectra illustrate the capability of the system to distinguish between some biological and nonbiological aerosols, and among several types of laboratory-generated biological aerosols. We suggest improvements needed to make our system field portable. © 1999 John Wiley & Sons, Inc.* Field Analyt Chem Technol 3: 221–239, 1999