Investigation of optical properties and sensing potentials of some organic dyes in polymeric matrices

In this thesis, spectral properties and selective sub-nano molar response towards the ionic silver of the newly synthesized Y10 dye has been investigated. The excitation and emission spectra of the dye has been recorded in the solutions of tetrahydrofurane (THF), diclorometane (DCM) and ethyl alcohol (EtOH). Herein we investigated spectral properties of the fluorescent Y10 dye in plasticized polyvinyl chloride (PVC) polymethyl methacrylate (PMMA) and in ethyl cellulose (EC). In addition to the plasticizer the lipophilic anionic additive and ionic liquid were also utilized and effect of these additives on the spectral response has been evaluated. The Y10 dye exhibited better spectral response in EC. In later studies the EC has been used as matrix material. Response towards the ionic silver has been investigated in phosphate buffered solutions at pH 7.06 for the IL-Free and IL-Doped composites. The best limit of detection (LOD) value has been reported as 1.1x10-15 M silver. The decay time measurements were used to explain the mechanism behind the response. While the IL-Doped films exhibiting a linear response for the concentration range of 10-4-10-12 M, the electrospun fibers made up of the same material exhibited the linear response for the concentration range of 10-8-10-12 M. The EC doped Y10 dye exhibit as selective spectral response towards silver in presence of excess amounts of mercury(II), aluminum(III), calcium, copper(II), iron(III), potassium, manganese, magnesium, and lead at neutral pH. When the dye doped into EC along with appropriate additives can be used as an emission based sensor for silver for a large linear concentration range of 10-12 to 10-4 M.