Deriving Realistic Applications From Unusual Photophysics and Conjugation Chemistry of Carbon Dots

Abstract

Fluorescent carbon dots (CD) has gained tremendous attention from researchers for their newlinefascinating optoelectronic properties, with intriguing advantages like facile synthesis, negligible newlinephoto-bleaching, high stability, low cost, etc. It has been utilized in the arena of biomedicine, newlinephoto-catalysis, sensors, etc. However, incorporating the CDs in DNA and polymer followed by newlinethe formation of different novel biomaterials is highly demandable in various bio-applications and newlineneeds to be addressed sooner than later. This thesis is a result of research efforts dedicated to newlineexploring uncommon photophysical aspects of CD and their ability to conjugate with DNA and newlinepolymer for interesting applications. newlineChapter 1 of the thesis discusses a few basic concepts of CD which are important to newlineunderstand the research delineated in subsequent chapters. The chapter discusses CD substrates, newlinesynthesis, characterization techniques, and photoluminescence mechanisms. CD-based hydrogels newlineand their applications in the field of drug delivery, antibacterial photodynamic therapy, newlinenanofabrication, biosensors, cell imaging, etc are also discussed. newlineIn chapter 2 of this thesis, an unusual photophysical behavior of the carbon polymer dot newline(CPD) is explored that showed a red shift in the emission after EDC addition, due to enhanced newlinecrosslinking. The CPD shows different photophysical properties depending on the amide bond newlinebreaking as a function of pH that is used to distinguish between normal and cancerous cells newlinethrough in vitro bioimaging. newlineChapter 3 reports the investigation of Aggregation Induced Emission (AIE) property of newlinethe CDs that showed strong yellow color due to AIE. After base treatment, the yellow color newlinegradually transforms to blue color because of the pH-triggered disintegration. newlineIn chapter 4 of the thesis, a conjugation strategy to form DNA-CDs-polymer-based hybrid newlinehydrogel is reported, having self-healing and shape memory properties for trackable drug delivery newlineapplication. This research finding also shows that CD-based hybrid hyd