Design, Synthesis, and Applications of Carbon Dots with Controlled Physicochemical Properties
Modification of carbon dots (CDs) is essential to enhance their photophysical newlineproperties and applicability. Physical (e.g., composite material blending, coreshell architecture) and chemical (e.g., doping, surface passivation) methods exist to modify CDs. Different precursors can impart varied functionalities and heteroatomic dopants on CDs. Despite several modification strategies, the reproducibility and scalability of CDs still need to be improved. Newer approaches for modifying CDs are thus essential to ensure lab-to-lab and batchto-batch consistency. Our study focused on developing novel strategies for the physicochemical modifications of CDs. The theoretical simulation we performed for surface-functionalised CDs with the aid of density functional theory and time-dependent density functional theory helped to predict the mechanism of photoluminescence (PL) and to analyse the effect of hydrogen bonding on the newlineproperties of CDs (Chapter 3). We have developed a novel and general method for preparing amine functionalized CDs from modified paper precursors (Chapter 4). This strategy allows us to prepare CDs with customized functionalities, alleviating the post-synthesis modification. A novel ionimprinting strategy involving CDs synthesised from modified paper precursors newlinewas also developed through our research (Chapter 5). In another work, we utilized silk fibers as a matrix for immobilising CDs (Chapter 6). CDs prepared from mulberry leaves were fed to silkworms to produce CD-embedded silk fibres, which could be used to detect dopamine. In addition, we prepared CDs newlinefrom an unreported natural source (frankincense), which were used to detect lead ions (Chapter 7). We demonstrated the heavy metal sensing application of these newlineCDs in combination with a UV-light LED chip and a smartphone, which is relevant in resource-limited areas. The research results presented in the thesis are expected to inspire further investigations and applications related to CDs.