Sustainable carbon quantum dots from Mahua (Madhuca longifolia) for biomedical and environmental applications
Daray Soren, Jagannath P. Panda, Jaykishon Swain, Anulipsa Priyadarshini, Subrat Swain, Jasmine Swain, Rashmirekha Pati, Soumya R. Mohapatra, Yasobanta Das, Raghabendra Samantaray, Rojalin Sahu
Abstract
With the goal of creating environmentally friendly therapeutic Carbon Quantum Dots (CQD), we explored the potential of a wildflower, Mahua ( Madhuca longifolia ), as a carbon source. The Mahua tree holds significant socio-economic importance in eastern and central India. Applying a conventional hydrothermal technique, we synthesized CQDs of a tiny size of ~ 5.77 nm. To authenticate the synthesized CQDs X-ray diffraction (XRD), FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS), zeta potential, transmission electron microscopy (TEM), atomic force microscopy (AFM), UV-visible spectroscopy, and photoluminescence spectra were employed. The synthesized CQDs exhibited exceptional stability over a storage period of one month and demonstrated pH-sensitive fluorescence behavior, making them suitable for biomedical and environmental applications. Metal sensing studies revealed that CQDs are highly selective in sensing Fe 3+ ions in the presence of other transition and alkali metal ions. Antifungal assays conducted on pathogenic Aspergillus Niger and Fusarium Oxysporum showed significant inhibitory effects of CQDs. Cytotoxicity studies on dendritic cells revealed an IC50 value of 3.1 for CQDs, indicating their implied biomedical applications. Additionally, antibacterial assays against Staphylococcus aureus were studied using CQD extract. Together, these findings indicate a potential use of eco-friendly carbon-based QDs in environmental monitoring and biomedical diagnostics.