Functionalized Two-Dimensional Carbon Nitride Nanodots Detect and Reverse Lead Toxicity in the Physiological Milieu

Despite the significant development of graphitic carbon nitride (g-C₃N₄) as a catalytic material, the biomedical application of this compound is rarely discussed in the existing literature. For the first time, we report on the synthesis of citrate-capped C₃N₄ nanodots (C-C₃N₄ NDs) and their potential application as a nanomedicine against lead poisoning. The physicochemical properties of the nanodots have been explored extensively using microscopic and spectroscopic tools. The generation of a significant amount of reactive oxygen species (ROS) has been witnessed for the as-synthesized citrate-capped nanodots. The C-C₃N₄ NDs can effectively bind to Pb(II), leading to the formation of a stable, soluble complex to eliminate Pb(II) from circulation. In addition, it has been demonstrated that the complex can be detected using spectroscopic tools, thereby making the nanodots potential markers for Pb(II) detection. These biocompatible NDs have also been found to have the potential to protect cellular components from ROS-associated damages while maintaining the cellular eustress condition. The present study establishes the dual action of C-C₃N₄ NDs as a potential lead detector as well as an alternative, nontoxic, biocompatible solution against lead toxicity.