Systematic review of carbon quantum dots (CQD): Definition, synthesis, applications and perspectives

The optoelectronic properties and the high biocompatibility of carbon quantum dots have made them one of the most novel and studied nanomaterials in recent years. Several application areas have used them as an efficient, economical, and environmentally sustainable tool. This review article is divided into five sections. The first unit presents the classification, description, and distinction of different types of quantum materials, emphasizing significant structural differences. The second section delves into carbon quantum dots, detailing the synthesis routes and presenting the mechanisms and variables considered in each case. The third section explains the chemical structure, stability, and related optical behaviors in detail. The fourth section highlights the most prominent applications of CQDs, such as the development of sensors, the photocatalysis of pollutants, imaging, nanomedicine, the oil and gas industry, cancer treatment, plant growth promoter and antibacterial applications. In the Fifth section, challenges and perspectives are discussed. To conduct a systematic analysis of the information, a large volume of data from the literature related to each section is processed, and a meta-analysis is developed for a more exhaustive processing of the information.