Polaritonic Enhancement of Near-Field Scattering of Small Molecules Encapsulated in Boron Nitride Nanotubes: Chemical Reactions in Confined Spaces

Nanotubes have been extensively utilized as nanocontainers for molecules and as nanoreactors for chemical reactions in confinement, with the potential for applications in hydrogen storage and catalysis. We show that phonon polaritons of boron nitride nanotubes (BNNTs) enhance the near-field vibrational spectra of molecules in close proximity to the surface. By encapsulating C₆₀ fullerene in BNNTs, we reach a sensitivity level of a few hundred molecules. Furthermore, we show by the photopolymerization of C₆₀ that products of chemical reactions inside the tubes can be identified, so long as their vibrational signatures lie in the reststrahlen band of the BNNT.