Detection of gas-phase explosive analytes using fluorescent spectroscopy of thin films of xanthene dyes

A sensing system for explosives is demonstrated. The sensor is based on a layered structure of approximately a monolayer of a fluorophore deposited onto a few hundred nm of a transparent polymer, supported by a glass slide. The fluorophores are inexpensive xanthene laser dyes, which have high quantum yields, and the polymers are commodity materials polymethylmethacrylate and polyvinylidene difluoride. The different fluorophore/polymer combinations give different emission responses to analytes, including both signal quenching and enhancement. The pattern of responses can be used to identify the analyte. The common explosives TNT, PETN, RDX, HMX, and TATP as gas phase species can all be uniquely identified at room temperature using only the natural vapor pressure of the explosive to deliver sample to the sensor