Carbon Dots an Integrative Nanostructure for Fluorescent Bio-imaging, Targeted Delivery of Medication and Phototherapy in Malignancy: A Review

Silent onset and metastasis in tissues make cancer the most devastating illness globally. Monitoring the growth of the tumour and delivering drugs to specific tissues are some of the major issues associated with treatment. However, with an improved understanding of tumour microenvironments and advancements in nanocarriers of drugs, novel nano-targeting pathways that can be utilised by nanocarriers have been developed. Carbon Dots, with their tiny size and outstanding physicochemical features, are an emerging category of carbon nanostructures that have attracted a lot of curiosity. Multitudinous attempts and extensive studies have been undertaken by many researchers regarding the synthesis of Carbon Dots and their applications in various fields. These studies have explained that the synthesised Carbon Dots have versatile surface functionalities, high luminescence, and excellent biocompatibility. This article focuses on recent developments in synthesis approaches, carbon precursors used, and applications of Carbon Dots, specifically within the biomedical field, with a particular focus on cancer. Carbon dots synthesised from a variety of precursors can act as prominent candidates for bioimaging and drug carriers and are used in cancer phototherapy. In this article, Carbon Dots are summarised based on their bright luminescent properties, distinct structure, drug loading capacity, and near-infrared (NIR) emission. Carbon dots, employed as tumour theranostics, can serve as an alternative to synthetic fluorescent dyes. They fulfil the role of bioimaging agents and facilitate the precise delivery of drugs to cancer cells. Additionally, they exhibit excellence as phototherapeutic agents, featuring high nearinfrared (NIR) emission and minimal side effects.