Polaritonic Enhancement of Near-field Scattering of Small Molecules Encapsulated in Boron Nitride Nanotubes

TL;DR

This paper demonstrates that boron nitride nanotubes can significantly enhance near-field vibrational spectroscopy of small molecules, enabling detection of few hundred molecules and identification of reaction products via polariton gap signatures.

Contribution

It introduces a novel method of using BNNTs to improve near-field vibrational spectroscopy sensitivity and selectivity for small molecules.

Findings

Enhanced vibrational spectra of C60 molecules inside BNNTs

Detection of chemical reaction products via polariton gap signatures

Sensitivity limit of a few hundred molecules

Abstract

Near-field spectroscopy has been extensively applied recently to analyze collective optical properties of materials at the nanoscale. However, vibrations of small molecules were only recognizable in close proximity to a metallic resonator. We show that encapsulation in boron nitride nanotubes (BNNT) enhances the near-field vibrational spectra of C$_{60}$ fullerene, reaching a sensitivity limit of a few hundred molecules. Furthermore, products of chemical reactions inside the tubes can be identified, so long as their vibrational signatures lie in the polariton gap of the BNNT.