Raman and SERS spectroscopy of cucurbit[n]urils.

Cucurbit[n]urils (CB[n]) are a family of supramolecular hosts which can provide highly selective recognition based on their size (n). In this work we study their Raman spectroscopic signatures both experimentally and by molecular simulation and find systematic trends providing evidence of ring strain effects with size. Furthermore, we present for the first time their surface-enhanced Raman scattering (SERS) spectra utilizing both nanostructured surface and nanoparticle based approaches. Using SERS we can detect CB[n] at the ppb level and are able to distinguish between them in mixtures. Our study paves the way for utilization of CB[n] in highly sensitive, multiplexed, real time and high throughput molecular recognition assays based on SERS.