Cinnamon Bark Assisted Synthesis of Carbon Quantum Dots as Targeted Doxorubicin Drug Delivery Nanosystem

ABSTRACT Carbon quantum dots (CQDs) have emerged as an intriguing field of research for their small size, distinctive characteristics, and diverse uses across multifarious domains, such as disease treatment, bioimaging, biosensing, drug delivery, and various therapeutic prospects. Furthermore, the lack of research in green synthesis and biomedical applications highlights the necessity for further studies on sustainable methods for the production of CQDs.The present study aimed the synthesis of CQDs from two natural sources, namely, cinnamon and neem barks. The cinnamon bark successfully produced CQDs within 5 min, whereas the neem bark produced larger‐sized carbon nanoparticles (CNPs) at the same time interval. Dynamic light scattering (DLS) data and transmission electron microscope (TEM) images confirmed the formation of CQDs whereas FTIR spectra confirmed the presence of surface functionalization, which is required for conjugation with drug molecules. Finally, the as‐synthesized CQDs from cinnamon bark were conjugated with doxorubicin at different concentrations. The in vitro cytotoxicity study was carried out using HeLa cells as a model for cancer cells by the MTT assay method. It was observed that the CQD‐drug conjugates showed more cytotoxicity as compared to the free drug due to the drug and nanocarrier formulation successfully entering the cells through endocytosis.