Effect of doping and functionalization of carbon dots on their properties
At the present time, topically to study the possibilities of using carbon dots for biomedical applications. The creation of low-toxic nanosystems based on carbon dots that can replace toxic semiconductor quantum dots and are used in the creation of biosensors, bioimaging and theranostic agents is promising and has a novelty. In this work, carbon dots were synthesized by the hydrothermal method using glucose and soot from birch bark soot as carbon precursors. Aqueous solution of ammonia was used for doping with nitrogen atoms of carbon dots. The average sizes of carbon dots from glucose were to 14 nm, from birch bark soot - 49 nm. The difference in the sizes of carbon dots is due to the different nature of carbon precursors. The resulting carbon dots exhibit absorption in the ultraviolet region of the spectrum and luminescence in the blue-green region. The composition of functional groups on the surface of carbon dots represented by carboxyl, carbonyl, hydroxyl and epoxy groups. Functionalization with chromophore groups was made to change the properties of the obtained carbon dots. It has been established that the addition of chromophores changes the absorption spectra of carbon dots and shifts the luminescence spectra to the red region of the spectrum.