Optical Sensing of the Selective Interaction of Aromatic Vapors with Cavitands

Cavitands represent an important class of synthetic molecular receptors with significant potential for chemical recognition. We use surface plasmon resonance (SPR) to demonstrate this fact using several organic vapors (aromatic and non-aromatic analytes) and three cavitands. The three cavitands (abbreviated QxCav-1, MeCav-2, and PzCav-3) chosen for this study, had a different size and shape of the pre-organized cavity. QxCav-1 was found to have a marked preference for the aromatic compounds while MeCav-2 showed an insignificant response towards these analytes and PzCav-3 showed intermediate preference for some of these analytes. The recognition pattern reveals the importance of the cavity size for interaction and confinement of the analytes. Based on the results, it is expected that cavitands will have great potential for application in chemical sensing devices using optical transduction schemes such as SPR.