# Emerging Biomedical Applications of Carbon Dot and Polymer Composite Materials
## 5 Conclusions and Perspectives  
In summary, the sources, characteristics, and synthesis of CDs, as well as their biomedical applications, were highlighted herein with an emphasis on emerging applications. The review was presented in a manner that non-chemists and other professionals may readily comprehend regarding the concept of CDs. CDs as well as carbon-based composite materials have evolved into being used in a variety of biomedical applications owing to their distinct physiochemical, biocompatible, immune quiescent, and other features. The key contribution of this review is the proposed following future framework: (1) whether various sources produce CDs with versatile biomedical applications, (2) comprehending the pharmacology of CDs in the body as well as their ultimate fate in bodily systems, (3) determining how CDs disintegrate the BBB to enter the brain, whether alone or in combination with other chemical substances, (4) creating portable gadgets from carbon dot and composites allows biomedical specialists and environmentalists to undertake more effective work such as medical diagnostics, counterfeit detection, or pollution detection, and (5) establishing a program for the large-scale use of CDs in agricultural systems, such as fertilizers and storage, for the sake of both humans and the environment. Carbon dot-based biomedical applications are emerging, and significantly more is expected from them.  
A clear understanding of the fundamental property is required for new class materials of CD/polymer composites. Some state-of-the-art spectroscopic and electronic microscopic techniques could explain the fluorescence mechanism at the single-particle level. The  
Figure 6: Diagram of in vivo and in vitro glucose CDs (GluCDs) transport. In zebrafish and rat models, GluCDs cross the BBB without the necessity for conjugation to a targeted ligand for receptor-mediated transport. GluCDs have the ability to convey cargo to the CNS. In a yeast model, the absorption process of GluCDs needs glucose transporter proteins. The figure was depicted from [114], which is unrestrictedly accessed and distributed under the Creative Commons Attribution 3.0 International License ([[http://creativecommons.org/licenses/by/3.0/](http://creativecommons.org/licenses/by/3.0/)]([http://creativecommons.org/licenses/by/3.0/](http://creativecommons.org/licenses/by/3.0/)) (accessed on 14 August 2022)).  
new route of synthesis and modifications by doping and polymer conjugation is expected to play a significant role in biomedical sciences. In the future, the fluorescence off/on mode of CD/polymer composites can be applied to the ratiometric detection of important bioanalytes. It would not be far away from transferring that laboratory-scale knowledge into the commercial and industrial applications of CD-based polymers and CD composite materials. The preclinical study of CD/polymer demonstrates that drug delivery, cancer therapy, and others are very bright in the future. More specifically, the lab-on-a-chip and diagnosis with the naked eye are one of the few examples that could soon become vibrant in the biomedical sciences.  
Writing--original draft preparation, G.O.A., S.M.S., and J.H.R.; writing--review and editing, G.O.A., S.M.S., and J.H.R.; supervision and funding acquisition, J.H.R. All authors have read and agreed to the published version of the manuscript.  
This research was supported by Wonkwang University in 2020.  
Not applicable.  
The authors declare no conflict of interest.