Innovative Methods of Therapy Using Quantum Dots

Quantum dots (QDs) are semiconductor nanocrystals with a size in the range of 1–10 nm. They are created on the basis of inorganic semiconductor materials Si, InP, CdSe, etc., and are coated with a stabilizer monolayer. QDs have unique optical, electrical, electrochemical, and catalytic properties. The crystal core of a quantum dot contains about 100–100 000 atoms. Quantum dot size is comparable to the wavelength in the material on the basis of which it is made. Inside a quantum dot, the potential energy of an electron is lower than outside it, and thus the motion of the electron is limited in all three dimensions. The energy levels of electrons inside a quantum dot are discrete and are separated by regions of forbidden states. The behavior and properties of these objects are described not by classical physics, but by quantum mechanics. The current review focuses on applications of QDs such as providing high-quality bioimaging of tumors in vitro and in vivo, visualization of drug transportation, targeted drug delivery, photothermal and photodynamic therapy, cell sorting activated by fluorescence, and use in biosensors. Emphasis is placed on the technology of accurate detection and inhibition of SARS-CoV-2 using quantum dots.