Surface Plasmon Polarition Pumped Explosives Sensors

The goal of this project is to develop novel hybrid forms of matter that support metastable electronic states that, in turn, are highly responsive to changes in the chemical state of the surface of the material. The strategy is to create excited (metastable) electronic states by populating normally unoccupied states in the conduction band. To achieve this, plasmonic materials, such as Au, Ag. Al, etc. are mated with semiconducting materials. By exciting surface plasmon polaritons, we pump energy into the semiconductor either by injecting electrons into its conduction band (hot electrons) or energy transfer by inelastic scattering of surface plasmon polaritions. By establishing a unstable equilibrium of excited states, we produce a material with an electron state that is extremely sensitive to pertubations of the electronic environment. By functionalizing the surface of this hybrid material with molecular receptors that target ammonium nitrate, a common explosive used in IED, a highly sensitive explosive sensor is realized.

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Funded

• Funded by the Office of Naval Research (N00014-20-2433).