STUDY OF ORGANIZED MEDIA USING FEMTOSECOND SPECTROSCOPY AND CONFOCAL MICROSCOPY

Abstract

Self-organized nanostructures play a crucial role in a wide range of natural phenomena ranging from molecular recognition (e.g. enzyme-substrate, antigenantibody interaction), to a more general case of unusual chemistry in confined environments. Due to the confinement and local interaction, the biological activity and dynamics in these assemblies are significantly different from those in ordinary solutions. In recent years, ultrafast time resolved spectroscopy revealed substantial amount of new information on these systems.The experimented results has stimulated a large body theoretical studies and in particular, large scale computer simulations. The main motivation of this thesis is to understand the role of confinement on the spectroscopy and dynamics with both temporal and spatial resolution. In the present thesis, we studied different organized media using femtosecond upconversion, time resolved confocal microscopy and fluorescence correlation spectroscopy (FCS). In bulk, all chemical informations are averaged over an exceedingly large number of molecules of the order of the Avogadro number. Recent single molecule studies have demonstrated variation of properties of individual molecular systems in an ensemble. This has completely revolutionized our understanding of chemistry.The research was carried out under the supervision of Prof. Kankan Bhattacharyya of the Physical Chemistry division under SCS [School of Chemical Sciences]The research was conducted under CSIR fellowship and DST research gran