Highly Novel Detection Approaches to Human Volatile Organic Compound Signature Identification

The ability to perform rapid, highly sensitive and selective detection of a complex Volatile Organic Compound (VOC) signature profiles is important for applications ranging from acute situational health and safety assessment to suspect/target identification. Commercial gas sensors employ a number of different transduction mechanisms depending on the nature and reactivity of the gas and include systems based on optical, electrical and mass detection. Recent advances in gas sensor technology have provided even more sensitivity and are poised to increase the sensor specificity in analysis of complex VOC profiles in compact, low-cost formats. Ultimately, a VOC detection platform must be compact and amenable to analysis of a range of targets (selectivity), provide accurate point exposure sensing limit detection and produce reliable analysis with low false alarm rates. The ability to multiplex high sensitivity and selectivity in a robust, rechargeable, harsh environment will provide the Air Force with a tool to meet the goal of complex VOC profiling for positive or negative identification of suspects/persons of interest and other airborne screening applications. To this end, Nanohmics proposes to continue the development of a novel detection device that meets the requirements for high sensitivity and high selectivity analysis of complex VOC profiles. The core of the technology is an array of independently-addressable, chemoresistive sensors that have robust nanotraces fabricated using a novel technique. This technique eliminates the limitations of scale and response inhomogeneities of vapor grown semiconducting nanowires and carbon nanotubes. BENEFIT: Numerous instruments have been developed to automate the process of gas analysis. Optical systems are often too bulky, and such direct electrical systems that rely on chemoresistive changes to semiconductor materials have shown great promise in commercial gas sensors. Nanohmics proposed use an emerging semiconductor fabrication technique is ideal for manufacturing sensor arrays. Our goal is to be the first to market such a technique and thus enable the necessary sensor platform for screening sensitization compounds and ultimately use in odorprint detection. The process will enable multiplex gas sensors to be scale to the commercial level. A compact, affordable sensor device tailored for the covert analysis of complex VOC profiles for suspect identification with the ability to perform all aspects of sample collection, multiplex detection, and complex signature analysis using modest-density arrays will be a compelling tool for the Air Force.