The optical identification of bioaerosols in the atmosphere and its discrimination against combustion related particles is a major issue for real-time, field compatible instruments.
Our recent work is focused on embedding advanced pump-probe depletion spectroscopy schemes in a portable instrumen to discriminate amino acid containing airborne particles (bacteria, humic particles, etc.) from poly-cyclic aromatic hydrocarbon containing combustion particles (Diesel droplets, soot, vehicle exhausts) with high selectivity.
Our real-time, multi-modal device provides, in addition to the pump-probe depletion information, fluorescence spectra (over 32 channels), fluorescence lifetime and Mie scattering patterns of each individually flowing particle in the probed air. We have also successfully transferred a similar scheme to liquids, demonstrated the detection of bacteria in flowing water for real-time pollution monitoring applications.