The main challenge to exploiting plasmons for gas vibrational mode sensing is the extremely weak infrared absorption of gas species. In this work, we explore the possibility of trapping free-gas molecules via surface adsorption, optical, or electrostatic fields to enhance gas-plasmon interactions and to increase plasmon-sensing ability. We discuss the relative strengths of these trapping forces and find gas adsorption in a typical nanoribbon array plasmonic setup produces measurable dips in optical extinction of magnitude 0.1% for a gas concentration of about the parts per thousand level.
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Acknowledgments. This research is supported by grants from the U.S. National Science Foundation (ECCS 1809723 to T.L. and S.-H.O. and ECCS 1809240 to S.-H.O.). S.-H.O. also acknowledges support from Seagate through the MINT consortium at the University of Minnesota.