Improved Conversion of Carbon Quantum Dots From Tulsi Leaves via Hydrothermal Processing for Antibacterial and...

The increasing demand for sustainable nanomaterials with effective antibacterial and wound-healing potential motivated the development of carbon quantum dots synthesized through an improved hydrothermal conversion approach using natural precursors such as Tulsi leaves. The synthesis conditions were optimized to achieve improved conversion efficiency and a higher number density of CQDs. The carbon quantum dots are synthesized with varying number density and size and verified using a variety of structural, chemical, and thermal analyses. The size and shape of the quantum dots are further examined through various imaging techniques like TEM, SEM, and AFM. The photoluminescence investigation confirms the broad range of excitation-emission phenomenon as a function of number density and size. The electrochemical behavior is further worked out to find their electronic, ionic, and redox properties. The antibacterial activity of the quantum dots against S. aureus has been investigated in detail, and their ability to effectively cure bacterial wounds in a rat model has also been examined. The swab test is used to further investigate the bacterial killing efficiency by culturing the bacterial colonies on an agar plate. In brief, strong and tuned fluorescence and antibacterial behavior of quantum dots from natural resources can be a potential biomaterial.