Biomedical application of carbon quantum dots: A review

The many beneficial properties of carbon quantum dots (CQDs) have led to their increased interest as a potential material for use in various biomedical applications. These properties include fluorescence, biocompatibility, low toxicity, small size, ease of modification, low production costs when scaled up, and versatile conjugation with other nanoparticles. In addition, the development of theranostic nanomedicine, bio-imaging of cells and bacteria, and multifunctional diagnostic platforms have all shown promise. Optical imaging, cancer therapy, drug delivery systems, gene delivery, antimicrobial activity, bioimaging and biosensors, photothermal and photodynamic therapy, pharmaceutical formulations, and more are all parts of CQD research that this review succinctly summarises. The literature primarily describes two approaches for synthesizing CQDs: the top-down approach, which involves disassembling a larger carbon structure into nanoscale particles, and the bottom-up approach, which involves creating CQDs from smaller carbon units (small organic molecules). The literature has a large number of review articles about the synthesis and uses of CQDs. Nevertheless, there isn't a comprehensive paper like this that goes over the entire process of creating and using CQDs made of tiny organic compounds. Based on the available literature, we have compiled the research progress on CQDs in this review, including its synthesis from small organic molecules (bottom-up approach), applications in the fields of bioimaging, drug/gene delivery systems, photocatalytic reactions, photodynamic therapy (PDT), and photothermal (PTT) therapy, as well as methods of thermal decomposition and microwave irradiation and ultrasonic treatment. Lastly, the difficulties and potential course of CQDs are explored. Our conversation also broadens to cover CQDs function in nano- medicine, the field that many believe will shape biomedicine in the years to come. The results of this study will help the biomedical research community realise the potential of CQDs to solve many present-day technological issues.