Heavy Atom Effect on Metallole Nanoaggregates and Their Explosive Sensing Applications

Electronic and optical properties of metallole nanoaggregates (M = Ge and Sn) were investigated. Amplified photoluminescence (PL) properties, absolute quantum yields (QY), and critical aggregation concentrations for the metallole nanoaggregates were measured. The an aggregation-induced emission enhancement (AIEE) property decreases as the central atom becomes heavier in the metallole ring. Detection of TNT was achieved by the quenching PL of the metallole nanoaggregates. A linear Stern–Volmer relationship was observed for the detection of TNT.

Explosive sensing with insect-based biorobots

ABSTRACTStand-off chemical sensing is an important capability with applications in several domains including homeland security. Engineered devices for this task, popularly referred to as electronic noses, have limited capacity compared to the broad-spectrum abilities of the biological olfactory system. Therefore, we propose a hybrid bio-electronic solution that directly takes advantage of the rich repertoire of olfactory sensors and sophisticated neural computational framework available in an insect olfactory system. We show that select subsets of neurons in the locust (Schistocerca americana) brain were activated upon exposure to various explosive chemical species (such as DNT and TNT). Responses from an ensemble of neurons provided a unique, multivariate fingerprint that allowed discrimination of explosive vapors from non-explosive chemical species and from each other. Notably, target chemical recognition could be achieved within a few hundred milliseconds of exposure. Finally, we developed a minimally-invasive surgical approach and mobile multi-unit electrophysiological recording system to tap into the neural signals in a locust brain and realize a biorobotic explosive sensing system. In sum, our study provides the first demonstration of how biological olfactory systems (sensors and computations) can be hijacked to develop a cyborg chemical sensing approach.SUMMARYWe demonstrate a bio-robotic chemical sensing approach where signals from an insect brain are directly utilized to detect and distinguish various explosive chemical vapors.