Host-guest interactions in gas phase chemical sensing of permethyl-6I-alkenoylamino-6I-deoxy-â-cyclodextrin derivatized porous silicon
Abstract
Porous silicon surface was modified by photochemically activated hydrosilylation reaction with permethyl-6(1)-alkenoylamino-6(1)-deoxy-beta-cyclodextrins. In the presence of controlled amounts of various organic molecules in gas phase photoluminescence response from this derivatized porous silicon revealed formation of host-guest complexes between P-cyclodextrin and detected molecules.
The strongest modification of photoluminescence response was observed for aromatic compounds that have optimal molecular size for strong interaction with beta-cyclodextrin cavity. For low concentrations of aromatic molecules we observed PL enhancement most probably due to electron transfer from beta-cyclodextrin-analyte complex to porous silicon.
For higher concentrations-after saturation of the beta-cyclodextrin sites - a combined response with dominant PL quenching was observed. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.