TAGRA 2024

Abstract
Carbon Quantum Dots (CQDs), a new generation of carbon-based nanomaterials, have attracted significant attention in scientific research due to their unique optical properties, high biocompatibility, low toxicity, and excellent chemical stability. Their low production cost and versatility in applications such as bioimaging, biosensors, drug delivery, and energy storage, especially compared to conventional quantum dots, make them highly valuable.
Given that hen nails are rich in organic compounds such as proteins and polysaccharides, they are an excellent and sustainable carbon biomass source for CQD synthesis. The nail's organic content was converted into CQDs with desirable optical and structural properties using the solvothermal method. This method not only aids in waste reduction but also aligns with the principles of green chemistry, leveraging a natural, abundant, and biodegradable resource.
Photoluminescence (PL) analysis of the synthesized CQDs showed an excitation wavelength of 330 nm and an emission wavelength of 430 nm. Key parameters affecting synthesis, including solvent selection, synthesis temperature, reaction time, pH, and carbon source concentration, were studied and optimized.
Ethanol as a solvent, 160 ◦C as synthesis temperature, pH=12, and nail solution 500 ppm were selected.
Additionally, the CQDs were doped with nitrogen, sulfur, and fluorine to enhance their properties. The synthesized CQDs were successfully employed as fluorescent sensors for detecting heavy metals such as lead (Pb) and cadmium (Cd) in water samples. Structural and functional characterization was performed using FTIR, PL, and UV-Vis spectroscopy, to analyze the size distribution DLS technique and CHNS for elemental analysis.