Vol.:(0123456789) 1 3 Carbon Letters https://doi.org/10.1007/s42823-023-00505-3 ORIGINAL ARTICLE Online ISSN 2233-4998 Print ISSN 1976-4251 Green synthesis, characterization and biomedical applications of Centella asiatica‑derived carbon dots Bothe Thokchom 1  · Santosh Mallikarjun Bhavi 1  · Megha B. Abbigeri 1  · Arun K. Shettar 1  · Ramesh Babu Yarajarla 1 Received: 3 February 2023 / Revised: 16 March 2023 / Accepted: 26 March 2023 © The Author(s), under exclusive licence to Korean Carbon Society 2023 Abstract Medicinal plant-derived carbon dots are eco-friendly and possess therapeutic properties. Among the medicinal plants studied throughout the world, Centella asiatica (L.) Urb. is known for its medicinal values, especially its neuroceutical and cog- niceutical properties. This work discusses the green synthesis of carbon dots (CDs) using C. asiatica leaves as the carbon source via fast and cost-efective microwave-assisted method, and its physico-chemical characterization via UV–visible, fuorescence and FTIR spectrometry, XRD, SEM, AFM, TEM, SAED, EDX and zeta potential analyses. The study revealed quasi-spherical CDs having size ~ 3–6 nm, polycrystalline nature, and presence of various functional groups like –COOH, –H, =CH 2 and C–O–C with UV absorption peaks at 213 and 322 nm. Interestingly, the C. asiatica-derived CDs exhibited blue fuorescence under UV with maximum emission wavelength of 460 nm when excited at 400 nm. Further, these CDs were evaluated for their biological applications, which uncovered their potential in therapeutics such as antimicrobial proper- ties against both Gram-positive and Gram-negative bacteria at a dose of 10 μg, strong antioxidant activity with IC 50 values of 165.28 and 128.48 μg mL −1 in DPPH and H 2 O 2 assays, respectively, and profound anti-infammatory activity with IC 50 value of 106.20 μg mL −1 in protein denaturation assay. The CDs were also assessed for cytotoxicity using whole blood cells and were found to be safe for in vitro administration. Thus, the C. asiatica-derived CDs can be exploited for their potent biomedicinal properties. * Ramesh Babu Yarajarla rameshy@kud.ac.in 1 Department of Applied Genetics, Karnatak University, Dharwad, Karnataka 580003, India