Quantum dot are artificial nanostructures or tiny particles of a semiconducting material with diameters in the range of 2-10 nanometers which can possess many varied properties, depending on their material and shape. Quantum dots glow a particular color after being illuminated by light. When the quantum dots are illuminated by UV light, some of the electrons receive enough energy to break free from the atoms. They are used intensively in the development of fluorescence and FRET-based biosensors for ultrasensitive detection of biomolecules like: acids, enzymes, sugars, antibodies, and antigens. Quantum dots will also play an important role in the future of optoelectronics. Quantum dots have properties intermediate between bulk semiconductors and discrete atoms or molecules. Edelweiss Applied Science and Technology journal is an open access maintaining high standard quality articles of basic science.