Graphene Quantum Dot
1. Properties of graphene quantum dot
Graphene quantum dot is a carbon materials which is nanometer-sized object where the excitons are confined in all three spatial dimensions. GQDs have diameters below 20nm. It is a graphene fragments that are small enough to cause excitons confine in a quantum size effect. The popularity of GQDs are due to a unique physical and chemical properties such as high electrical conductivity, high surface area, good resistance to corrosion high thermal stability, high chemical stability in non-oxidizing environments and particular mechanical properties. GQDs are abundant available with low toxicity, high soluble in various solvents and can be equipped with functional groups at their edges, making it superior compared to inorganic semiconductor QDs. However, research on GQDs is still in an early stage and the full potential has not yet been unraveled.
For our project, we focus on the bio-imaging properties of GQDs. GQDs is successful in the field of biotechnology due to their excellent optical properties and extreme low cytotoxicity. Reports have revealed that significant weakening in cell activity on addition of up to 400µg of GQDs to 150µL of culture medium. (104 cells). The ability of the GQDs to penetrate the cell nucleus makes them promising for applications in drug delivery systems and as gene carriers. GQDs are easily to penetrate tumor cells (human lung cancer, A549) and human breast cells (MCF-7) with little cytotoxicity. GQDs can be used in biological imaging and drug delivery, as their ability to penetrate cancer cells and stems cells, which allow a wide range of applications like C60 nanoparticles. It has been proved to have long fluorescence lifetimes and good stability against photo-bleaching.
GQDs represent an exciting future for carbon materials, and for the future of environmentally benign devices. The versatile chemistry of the carbon element of GQDs makes that new carbon forms with new applications are being developed in spite of the fact that a wide knowledge base is already available.