Carbon dots (CDs) are emerging as versatile fluorescent nanomaterials due to their excellent properties such as high-water solubility, photostability, good biocompatibility, flexibility for surface modification, low toxicity and production costs. These characteristics make them preferable to their inorganic cousins Quantum Dots (QDs) and more suitable for biomedical applications, such as imaging, antibacterial therapy, drug delivery for cancer treatment, photodynamic therapy and antioxidative nanotechnology. Regarding the last field, CDs have proven to possess scavenging activity towards reactive oxygen species (ROS), which are chemical, highly reactive, oxygen-containing species including hydroxyl radical , singlet oxygen, superoxide anion, and hydrogen peroxide. This antioxidant capability allows CDs to act as effective agents capable of keeping the concentration of ROS low, preventing various diseases such as cancer, atherosclerosis, neurological disorders, asthma, hypertensions, local anaphylaxis or inflammation.