Synthesis of Carbon Quantum Dots using Basella alba L. Fruits: Characterization and Fluorescent-based Detection of Fe (III) Ions

Background: The synthesis of carbon quantum dots (CQDs) from Basella alba L. fruit using the hydrothermal method is investigated for heavy-metal detection. CQDs have gained significant attention due to their unique properties, including high photoluminescence, biocompatibility, and low toxicity. The utilization of natural sources such as Basella alba L. fruit for CQDs synthesis offers an eco-friendly and cost-effective approach. Methods: In this study, Basella alba L. fruit was chosen as a precursor for CQDs synthesis due to its abundance and potential for heavy-metal adsorption. The hydrothermal method was employed as it provides a simple and efficient route for CQDs synthesis. The process involves the hydrolysis and carbonization of the fruit extract under controlled temperature and pressure conditions. The resulting CQDs were characterized using various techniques such as UV-visible spectroscopy, FE-SEM, EDS, E-mapping, DLS, Zeta potential, PL spectroscopy, and FTIR. Results: UV-Vis confirmed the presence of CQDs via the observation of a distinct absorption peak. EDS spectrum revealed the formation of CQDs and other groups of elements present with it, which contribute to their stability and interaction with heavy metals. FESEM images showed that the synthesized CQDs possessed a uniform size distribution and exhibited a well-defined crystalline structure. The synthesized CQDs were then evaluated for heavy-metal detection. In addition, due to their unique surface properties and interaction with heavy metals, CQDs acted as an effective sensor. A series of experiments were conducted to investigate the sensitivity and selectivity of the CQDs towards various metal ions. The results demonstrated the superior performance of the synthesized CQDs in detecting Fe3+ ions, exhibiting high sensitivity and selectivity by quenching fluorescence when interacting with Fe3+ ions. Conclusion: The successful synthesis of CQDs from Basella alba L. fruit is reported. The characterization results confirmed the formation of CQDs with desirable properties for Fe3+ ions detection. The obtained CQDs demonstrated promising potential as efficient and eco-friendly sensors for Fe3+ ions detection in environmental and biomedical samples.