Explosive detection using high-volume vapor sampling and analysis by trained canines and ultra-trace detection equipment

Fisher, Mark; Sikes, John; Prather, Mark

doi:10.1117/12.542900

Cited by 7 publications

(1 citation statement)

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“…Hence, it is not only the electronic factors that are important in sensing but also how the analyte can physically interact with the sensing material. The leading luminescence-based sensors are currently based on conjugated polymers with hand-held devices already in the market. , …”

Section: Introductionmentioning

confidence: 99%

Effect of Dimensionality in Dendrimeric and Polymeric Fluorescent Materials for Detecting Explosives

et al. 2010

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Steady-state Stern−Volmer analysis is uniformly used to assess in solution the efficiency of a sensing molecule for a particular analyte. We use a combination of steady-state Stern−Volmer analysis and time-resolved photoluminescence (TRPL) to determine the underlying mechanisms by which fluorescent sensing materials comprised of fluorene-based chromophores sense nitro-based explosive analytes. The ability of two first-generation dendrimers comprised of bifluorene-containing chromophores to sense explosive analytes was compared with the chemically related polymer poly(9,9-di-n-octylfluoren-2,7-diyl). One dendrimer was planar with a single chromophore with the second having four chromophores tetrahedrally arranged around an adamantyl center. All the materials had high photoluminescence quantum yields of around 90% and were able to sense explosive analytes via quenching of their fluorescence. The three-dimensional dendrimer based upon the adamantyl core was found to have the highest Stern−Volmer constants for all the analytes tested with the planar dendrimer also proving to be on average superior to the polymer. The TRPL measurements showed that sensing occurred by a combination of collisional and static quenching with the proportion of collisional quenching being based on the number of aromatic units in the analyte. Steady-state fluorescence polarization anisotropy measurements of the three materials revealed that for the three-dimensional dendrimer an exciton can migrate between all of the chromophores, meaning that an exciton formed on one chromophore of the dendrimer can be quenched by an analyte interacting with a second chromophore. This gives rise to the potential for sensing response amplification and explains its superior performance to the planar dendrimer and polymer.

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Section: Introductionmentioning

confidence: 99%