engleski

Materials for passive sampling and optical sensing of explosives, and an active method for landmine detection

Light-emitting organic semiconductors are highly sensitive to trace vapours of explosives at ppb concentration levels and below. However, detecting trace amounts of explosives in field conditions is highly challenging, especially under variable environmental conditions. Preconcentration techniques allow the explosives to sorb and accumulate on a material over time, thus a higher concentration can subsequently be thermally desorbed and detected via a loss of emission from the organic semiconductors. We present results from field trials using honeybees to passively collect explosives from the environment prior to deposition on preconcentrator materials in the colony entrance and compare with lab results. To assess optimal preconcentration materials, different polymers were loaded with 2, 4-DNT and their retention and desorption characteristics were measured for a wide range of analyte concentrations, and thermal desorption temperatures. Camera-equipped drones were also used with signal-processing algorithms to monitor trained honeybees swarming around vapour plumes. We demonstrate an end-to- end methodology with promising results for humanitarian demining efforts.

Optical Sensing ; Explosives ; Honeybees

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