Vol. 11, Issue 10 (2022)

In green nanotechnology, carbonaceous nanomaterials have been widely used due to their potential for non-toxic, biocompatible, varieties of physico- chemical attributes and ease of functionalization. The varieties of carbon and graphane-based nanodots, nanoparticles, nanofibers and nanotubes have been widely used. The chemical and physical methods of carbon dots synthesis have limitations like toxicity, high cost and complexity to obtain pure CDs. Therefore, in the present study, the carbon dots were synthesized from mango leaf extracts of local cv. Alphonso via Hydrothermal method as a green approach. Because mango leaf is rich in phytochemicals like phenolics and flavonoids it can be used to functionalize the fluorescent carbon dots (CDs) via the hydrothermal method. Thus, two different temperatures 150 °C and 180 °C were used for synthesising the CDs. The UV-Visible spectra revealed the different optical reactivity of CDs in an aqueous solution. The fluorescence spectrum showed the excitation-dependent emission at different excitation levels of CDs. The highest emission of CD 180 after 24 hr dialysis was used to measure quantum yield, which was 5.94%. DLS analysis revealed the average diameter was 1.32 nm along with a zeta potential of -18.3 mV. The outcome indicated that the highly fluorescent and blue colour carbon dots were successfully synthesized from mango leaf extracts. Furthermore, the highly functionalized CDs can be used in the further application of nanoscience and in many other fields because of safe, non- toxic and cost-effective.