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.