Biomedical advances and clinical challenges of graphitic carbon nitride quantum dots: A comprehensive review

Abstract

Graphitic carbon nitride quantum dots (g-C₃N₄ QDs) have garnered significant attention due to their unique physicochemical properties, including high biocompatibility, tunable photoluminescence, excellent chemical stability, and ease of functionalization. These attributes have positioned g-C₃N₄ QDs as promising candidates for a wide range of biomedical applications, particularly in drug delivery, photodynamic therapy (PDT), photothermal therapy (PTT), bioimaging, and biosensing studies. Despite rapid progress, the field lacks comprehensive critical reviews specifically focused on the synthesis, characterization, and biomedical application domains of g-C₃N₄ QDs, as reviews often address bulk or two-dimensional forms. This review provides a comprehensive analysis of recent advancements in the synthesis, functionalization, and biomedical applications of g-C₃N₄ QDs, highlighting their role as multifunctional nanomaterials. Additionally, the safety profile and toxicological considerations of g-C₃N₄ QDs are critically examined to assess their suitability for clinical applications. This review concludes by discussing future directions, including strategies to enhance their optical properties, improve targeted delivery, and expand their applicability in emerging biomedical fields. By consolidating current knowledge, this article aims to serve as a valuable resource for researchers working on the translational development of g-C₃N₄ QDs and integrating them into practical devices in nanomedicine.