Abstract
CQD are small carbon nanoparticles smallerl than 10 nm comprising distinctive properties, which have become an obligatory tool for traceable targeted delivery, biomedical research, and different therapy applications. The objective of the present work was to consolidate the current literature on the synthesis, characterization techniques, and biomedical applications of CQD. Two types of synthetic methods viz. top-down approach and bottom-up approach were used for the synthesis of CQD. The top-down approach includes the arc-discharge method, laser ablation method, and electrochemical method. The bottom-up approach includes the thermal method, microwave-assisted method, hydrothermal and aqueous method, and the template method. In this review, we explain the recent progress of CQD in the biomedical field, focusing on their synthetic methods and characterization, followed by different applications. Carbon dots have extensive adequacy for in vivo and in vitro bioimaging and drug delivery studies. Although more cytotoxicity studies of carbon dots are needed, the data above suggest a bright future for carbon dots in drug delivery and bioimaging studies.