REAGENTLESS BIO-SAMPLING METHODS FOR IR DETECTION

Abstract

Currently there exists a critical need within the military and homeland defense for highly sophisticated yet, small, lightweight portable sensors and detection systems for identifying and quantifying biological and biowarfare agents (BWA) in both liquid and aerosolized form. Our proposed BWA detection system is based upon Fourier Transform Infrared Spectroscopy (FTIR), where the main advantages of this approach are that it is reagentless, operates in heterogeneous aqueous environments, and provides fast detection and high sensitivity/selectivity to bacterial spores with minimal false alarms. The key enabler to using FTIR for BWA detection is to develop selective and robust sampling protocols coupled to a miniaturized, portable FTIR unit. To that end, we have developed front-end liquid flow cells which incorporate electric field (E-Field) concentration methods for spores onto the surface of an Attenuated Total Reflection (ATR) IR crystal. IR spectra are presented which show collection and detection results with BG spores in water. The approaches we have developed take advantage of the fact that all spores are negatively charged in neutral pH solutions. Therefore, E-Field concentration of spores directly onto an ATR sampling element enables low level concentration measurements to be possible.