Carbon dots as a distinctive platform fabricated through a sustainable approach for versatile applications

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 703; p. 135135
• Main Authors: Radha Krushna, B.R., Sharma, S.C., Srinivasan, A.R., Sahu, Samir, Ponnazhagan, K., George, Augustine, Govardhan Rathla, K.S., Manjula, M.V., Shivakumar, V., Devaraja, S., Veera Vanitha, D., Nagabhushana, H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.11.2024
• Subjects: Anti-counterfeiting; Biomedical; Carbon dots; Fe3+ sensing; Food preservation; Nanocomposites; Plant growth; Polyvinyl alcohol; UV blocking; Nanocomposites; Plant growth; UV blocking; Food preservation; Polyvinyl alcohol; Carbon dots; Anti-counterfeiting; Fe3+ sensing; Biomedical
• ISSN: 0927-7757
• DOI: 10.1016/j.colsurfa.2024.135135

Red-emitting carbon dots (R-CDs) have garnered significant interest owing to its exceptional fluorescence (FL) characteristics. In this study, we present a one-pot solvothermal synthesis for producing biomass-derived R-CDs, utilizing Birch leaves as the primary raw material. The R-CDs display high solubility in ethanol and demonstrate deep-red emission at 625 nm with narrowband characteristics. After conducting a selectivity assessment with different metal ions, it is observed that R-CDs demonstrate exceptional sensitivity and specificity specifically to Fe3+. This demonstrates a linear relationship up to a concentration of 500 μM, with a detection limit of 0.302 μM (S/N=3). In this research, we created photoluminescent and transparent composites made from polyvinyl alcohol (PVA) with embedded fluorescent R-CDs, using the solution casting method for fabrication. The synthesized R-CDs exhibit robust and consistent FL in solution, whereas, the R-CDs@PVA nanocomposites (NCs) films are transparent and exceptionally flexible. The optimized 0.08 wt% R-CDs demonstrated the most effective ultra violet (UV) blockage across the UV-A (76.84 %), UV-B (74.86 %), and UV-C (78.46 %) region. However, PVA alone absorbed < 25 % of the light in all UV regions. The study explored the shape memory and FL characteristics of the R-CDs@PVA NCs changed under varying conditions such as water, temperature and pH. In alkaline conditions, the FL intensity of the R-CDs@PVA NCs increased due to the deprotonation of the R-CDs surface. In addition, R-CDs dispersed within PVA exhibit superior ink-free patterned substrates, proving to be advantageous for non-destructive template relief printing. Furthermore, R-CDs serve as effective anti-oxidants, combating 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and mitigating the oxidative stress (OS) in red blood cells (RBCs) induced by sodium nitrite (NaNO2). They aid in the restoration of essential stress indicators, encompassing lipid peroxidation (LPO), protein carbonyl content (PCC), total thiol (TT), superoxide dismutase (SOD), and catalase (CAT). Furthermore, R-CDs restored the damaged liver, kidney, heart, and pancreas by regulating biochemical parameters. Furthermore, incorporated R-CDs into red light-emitting diodes (R-LEDs) and white light-emitting diodes (W-LEDs), thereby enhancing plant growth efficiency. The results of this study highlight the possible of R-CDs as non-toxic, UV blocking agents suitable for developing edible coatings and packaging. These properties suggest their applicability in the food industry, anti-counterfeiting (AC) measures, and biomedical applications. [Display omitted] •Solvothermally prepared R-CDs from Birch leaves are environmentally friendly.•R-CDs show high sensitivity toward Fe3+ with a LOD of 0.302 μM.•Bright and stable fluorescence provides security against counterfeiting.•R-CDs@PVA NCs are beneficial for shape memory, relief template and food packing.•R-CDs are useful for the treatment of early ageing, internal stress distortion and thrombotic disorders.