One of the most significant advancements in the rapidly expanding field of nanotechnology is colloidal semiconductor nanocrystals, often known as quantum dots. Originally suggested as fluorescent biological markers, they are now discovering significant new applications in analytical chemistry owing to their promising optical, structural, and electrical properties. Carbon dots have attracted a lot of attention lately because of their sustainability, strong biocompatibility, water solubility, low cost of manufacture, and superior chemical stability. Two main methods are used to synthesize carbon dots; the first method is top-down technique, while the second method is bottom-up technique.  Enhancing the photoluminescence, electrical, and structural properties of carbon dots can be achieved via a dependable and versatile method called hetero-atom doping. Carbon dots are used in versatile fields such as; imaging, sensing, cancer treatment, drug quantitation, gene therapy, photodynamic therapy, photothermal therapy, and microorganism eradication. An overview of recent applications of quantum dots from 2011 to 2024 will be presented in this review, which has 50 references.