|In his Defense seminar|
Jiba Raj Acharya successfully defended his PhD degree at Department of Chemistry, Louisiana State University, USA. His PhD research was focused on "Design, Preparation and Studies of Ratiometric Fluorescent Chemosensors Based on the Attenuation of Excitation Energy Transfer". On behalf of all Nepalese Chemists, we would like to congratulate him for this achievement and we wish for his better future.
More about his research on his own words:
In this Ph.D. studies targeting on the control of excitation energy migration in conjugated systems, I designed surface-immobilized monodispersed oligo(p-phenylene ethynylene)s (OPEs) as general basis for thin-film ratiometric fluorescent chemosensors. The sensor molecules have been functionalized with a specific analyte receptor at one end and a linkage for the covalent attachment to a glass surface at the opposite end. Upon surface immobilization, they form a highly ordered monolayer with the receptors positioned at the monolayer surface. Analyte binding to the receptor causes attenuation of the HOMO–LUMO gap at the receptor terminus, leading to the ratiometric change in fluorescent emission. The thin-film sensors for L-cysteine, pH, Zn2+ and NO were prepared and studied in detail to uncover a number of unusual properties, thus demonstrating the potential of this platform as a universal foundation for designing a broad range of ratiometric fluorescent thin-film chemosensors. The use of two fluorophore based surface-immobilized thin-film sensor is a novel approach and provides more reliable, accurate, easy to operate, and quantify the ratiometric fluorescent signals generated upon analyte binding.
Check his paper: J. Am.Chem.Soc.2009, 131, 880-881