Abstract:
Bidentate ureido-dihomooxacalix[4]arene based supramolecular hosts (n-propyl 1 and tertbutyl 2) were processed into organic nanoparticles via a bottom up approach in which
a single step of re-precipitation was employed. These organic nanoparticles were then coupled
with gold nanoparticles on the surface, resulting in an organic – inorganic hybrid framework
(n-propyl H1 and tert-butyl H2). Photophysical studies of the organic nanoparticles and of the
hybrid material were performed. The size and morphology were determined by TEM and DLS
analysis. Moreover, the prepared hybrid frameworks were screened against various anions
using UV-Visible absorption and fluorescence spectrophotometry. H1 exhibited ratiometric
response towards iodide ion in aqueous medium, and colour change of the solution from
pink to light blue was observed. This hybrid material selectively and sensitively detected iodide
ion with detection limit of 8.3 nM and with almost no interference from other anions. H1 sensor
ability was also tested with artificial and real urine samples. H2 showed different responses and
no selectivity to any anion.