Carbon quantum dots: Multifunctional fluorescent nanomaterials for sustainable advances in biomedicine and agriculture

Abstract

Carbon quantum dots (CQDs) are emerging carbon-based nanomaterials characterized by exceptional properties, including strong and stable photoluminescence, low cytotoxicity, high chemical stability, excellent water solubility, and outstanding biocompatibility. These features make CQDs highly promising for diverse applications in both biomedical and agricultural fields. Notably, the physiochemical properties of CQDs can be finely tuned through various synthesis strategies and the selection of appropriate carbon precursors. This review begins by presenting the fundamental structure and optical properties of CQDs, followed by an overview of their synthetic approaches and precursor types. It then explores the wide-ranging applications of CQDs in agriculture—such as promoting plant growth, enhancing stress resistance, and detecting metal ions and environmental pollutants—as well as their biomedical uses, including bioimaging, drug delivery, gene delivery, biosensors, and photodynamic therapy are elaborated. The review concludes by emphasizing the immense potential of CQDs to transform future biomedical innovations and sustainable agricultural practices.