The paper presents the results of a study of the effect of carbon dots synthesized by the hydrothermal method on the strength of hydrogen bonds in water. For the first time, using Raman spectroscopy and genetic algorithms, the values of the change of the enthalpy of hydrogen bonds were obtained when carbon dots were suspended in water. According to the calculations, the energy of hydrogen bonds in water is equal to 15.5±0.2 kJ/mol, and in an aqueous suspension of carbon dots, it is 14.8±0.2 kJ/mol. The results obtained make it possible to assess the safety of the studied carbon dots as biomedical nanoagents from the point of view of the effect on hydrogen bonds in biological tissue.
This study is devoted to a new approach to solve the problem of pH (in range of pH from 5 to 8) and temperature (in range of 30-45°C) measurements at nanoscale level, by using carbon dots (CDs), prepared from citric acid. These 10 nm sized nanoparticles with luminescence quantum yield ~10% have broad unstructured luminescence spectrum in the range from 420 to 750 nm, which is sensitive to the change of the environmental parameters. Different influence of pH and temperature values on luminescence spectra of CDs in aqueous suspensions was observed. The CD-based nanosensor was developed for simultaneous determination of pH and temperature using artificial neural networks.
This study is devoted to the study of the effect of different cations (Na+, Cs+, NH4+) and anions (F-, Cl-) on colloidal and photoluminescent properties of CDs, obtained from citric acid. The obtained results are explained using the theory of ions hydration.
The article presents the results of a comparative analysis of the adsorption properties of detonation nanodiamonds (DNDs) with different surface functionalization (carboxyl and hydroxyl groups) with respect to folic acid (FA). A significant dependence of the adsorption activity of nanodiamonds on the type of functional surface groups was found. The amount of adsorbed FA on DNDs with hydroxyl groups is 3.5 times higher than the amount of FA adsorbed on DNDs with carboxyl groups, however, the bond strength of the hydroxyl groups of DND with FA is almost 300 times weaker than the bond strength in the DND-COOH+FA complex. Based on the experimental results and calculations of the charge distribution of the deprotonated FA molecule, a model for the interaction of DND with FA is proposed.