A comprehensive review on various synthesis approaches and application of inorganic and carbon quantum dots

Quantum dots (QDs) are nanostructures that are confined to a zero-dimensional electronic structure. QDs exhibit different optical and electronic properties due to variations in size, making them highly appealing for use in optoelectronics, photocatalysis, sensing, and biomedicine. Both inorganic quantum dots (IQDs) and Carbon Quantum Dots (CQDs) have been effectively employed as nanomaterials, due to their excellent photoluminescence properties, high levels of biocompatibility, and vast surface area. Variant synthesis methods have been recognized for their ability to control size, morphology, and surface chemistry. There are two main strategies for synthesizing these two QDs. One is top-down method and another is the bottom-up method. Further, green synthesis techniques and synthesis in ionic liquids have been discussed and reviewed. Application of QD in various fields such as LEDs, bioimaging, antibacterial activity, drug delivery, etc. has been discussed comprehensively. Finally, some perspectives and possible directions for the future development of IQDs and CQDs are discussed.