Індекс рубрикатора НБУВ: Г121.225-4 + Р. с03

Шифр НБУВ: Ж14252 Пошук видання у каталогах НБУВ 

Photoluminescence and absorption spectra of nematic liquid crystal 5CB doped with an anthraquinone dye (AQ) hare studied. An effective energy transfer from the fast relaxing S1 level of 5CB with intensive PL band at 410 nm to slowly relaxing AQ level with PL band at 724 nm is discovered. On the basis of these results we reconstruct the energy level diagram that explains the stages of energy transfer process in the host-guest system.

Covering of nanocrystals (NC) with a polyethylene glycol (PEG) envelop is a common way to increase their hydrophilicity, and compatibility with bio-systems, including increased retention time in the body. Colloidal semiconductor NC, also known as quantum dots (QD), particularly benefit from covering with PEG due to passivation of the inorganic core, while maintaining physical properties of the core. Despite many advantages of covering the surface with PEG, the covalent attachment of protein to hydroxyls of PEG is complicated. Here we propose a simple two-step approach for modification of PEG residues with subsequent covalent attachment of proteins. We were able to achieve specific NC targeting by means of attached protein as well as preserve their optical parameters (fluorescence intensity) in chemical reaction conditions. In the optimized protocol, ensuring removal of chemical byproducts by dialysis, we were able to omit the need for centrifugation (usually a limiting step due to particle size). The obtained NC-protein conjugate solutions contained 0,25x of initial unmodified NC amount, ensuring a low dilution of the sample. During all reactions the pH range was optimized to be between 6 to 8. The proposed approach can be easily modified for covalent targeting of different PEG-covered nanocomposites with proteins.