Highly Sensitive and Selective Explosive Detector Based on Nanoporous Silicon Photonic Crystal Infiltrated with Emissive Organics [Nanoproducts]

Emitech Inc. (www.emitechinc.com) is developing a porous silicon (PSi) microcavity (MC)-based fluorescent detector for explosives. It was initially funded by the Army Small Business Innovation Research Phase II contract (Figure 1). The sensory part of the device is composed of a nano-PSi photonic crystal with MC, infiltrated with fluorescent organics that are specific to target explosive vapors and particulates. It is important that the nanodevice structure provides an extremely large interfacial area between the sensory material and the analyte vapors leading to its highest sensitivity, which is critical for fast trace detection of low vapor pressure explosives. An important feature of the nanodevice is the real-time sampling system (integrated with sensory head) based on the proprietary thermal air-jet technology.