Cavitands at work: From molecular recognition to supramolecular sensors

Exploitation of the molecular recognition properties of a given receptor in analytical applications requires mastering of specific host-guest interactions at interfaces. This review outlines the issues involved in turning P-V-bridged cavitands into selective layers for mass sensors, as a case study for gas-solid interfaces. The specific interactions operating at each phase level can be ferreted out by use of MS and crystallographic analyses, respectively. Their influence on sensor selectivity can be enhanced by exposure of the guest (analyte) to a network of cooperative interactions encoded in a single cavitand receptor. On the other hand, high layer permeability - necessary to achieve fast and reversible sensor responses - increases non-specific dispersion interactions. Shifting of the balance towards selectivity without loss of reversibility represents the major challenge facing those wishing to venture into the field of supramolecular sensors. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).