Electrostatic, non-fluorescent trigger for aerosolized biological threats using fluctuation enhanced sensing.

The objective of this Phase I proposal is to perform a theoretical exploration of the fundamental and practical limits of detection by fluctuation enhanced sensing and statistical inference based sensing methods when applied to an electrostatic-based trigger for non-fluorescent biological warfare threats. To enable < 1000 ACPLA detection levels of bacterial spores in real-time, these statistical methods will be applied to electrometer noise patterns when particle concentrations produce electric currents that are at or below the characteristic signal-to-noise level of the electrometer. The proposed hardware design for the electrostatic trigger is based upon the Faraday cup electrometer design for detecting ionized/unipolar charged aerosol particles. The electrostatic trigger will be a modification of an existing electrostatic precipitator detection system that is currently being developed. To facilitate low detection levels of bacterial spores beyond conventional Faraday cup designs, a novel corona pre-charge section will be incorporated within the trigger. The corona pre-charge section will maximize the amount of imparted charge per spore, thereby resulting in the largest possible electric currents produced per spore as measured by the collector cup.