Author/Authors :
Pinnick، Alan نويسنده , , Ronald G.; Hill، نويسنده , , Steven C.; Nachman، نويسنده , , Paul; Videen، نويسنده , , Gorden; Gang، نويسنده , , Chen; Chang، نويسنده , , Richard K، نويسنده ,
Abstract :
We report the operation of an aerosol analyzer capable of measuring
the fluorescence spectra of single micrometer-sized bioaerosol particles as they flow
through the instrument. Particles entrained in an airstream initially traverse a cw
(continuous wave) (488 nm) "trigger" laser beam where their elastic scattering and
total fluorescence is measured with photomultipliers. When the elastic scattering
and/or fluorescence signals exceed preset levels, a 266 nm UV "probe" laser is
triggered to fire and illuminate preselected particles downstream from the trigger
laser. The UV laser-excited spectra of particles are measured with the instrumentʹs
image-intensified CCD detector that is gated to be on when the probe laser fires. We
demonstrate the ability of the instrument to capture the fluorescence spectra of
single micrometer-sized airborne biological particles. Such spectra should be useful
in differentiating between biological and non biological aerosols and in partially
characterizing airborne biological particles.
