Investigation of the utilization of some fluorescent organic dyes in modified polymer or sol-gel matrices as optical sensor agents

In the first part of this work, three different ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium thiocyanate and 1-butyl-3-methylimidazolium hexafluorophosphate were employed for the modification of acid- catalyzed tetraethyl orthosilicate (TEOS) based sol-gel matrix. Photophysical characteristics and emission based response of tris (bipyridine) ruthenium (II) dye to gaseous oxygen was investigated in these ionic liquid containing sol?gel matrix by spectrofluorimetric method. Effects of the ionic liquid type, ionic liquid concentration, dye concentration and some sol gel parameters such as acid catalyze concentration; pH, gelation time, TEOS/water molar ratios and drying temperature to the oxygen sensitivity were evaluated.In the second part, the photo physical characterization of synthesized carbazole bearing oxazolones (4-[4-(9H-carbazol-9-yl)benzylidene]-2-(4-nitrophenyl)-1,3-oxazol-5(4H)-one (3), 4-[(9-methyl-9H-carbazol-3-yl)methylene]-2-(4-nitrophenyl)-1,3-oxazol-5(4H)-one (5a) and 4-[(9-hexyl-9H-carbazol-3-yl)methylene]-2-(4-nitrophenyl)-1,3-oxazol-5(4H)-one (5b) were investigated in polymer matrix of polyvinylchloride (PVC) by using absorption and emission spectrometry. The response of the dye doped PVC films were also evaluated in terms of the effect of pH and sensitivity to some metal cations and anions. The immobilized dye, 3 was found to exhibit a selective response for Zn (II) ions in direction of decrease in fluorescence intensity. Besides the selectivity of the dye to Zn (II) ions, high quantum yield value, the response in nanomolar concentrations level and high linear working range makes the dye promising for optical zinc ion sensor designs.