Nanodiamonds exhibit exceptional colloidal properties in aqueous media that lead to a wide range of applications in nanomedicine and other fields. Nevertheless, the role of surface chemistry on the hydration of nanodiamonds remains poorly understood. Here, we probed the water hydrogen bond network in aqueous dispersions of nanodiamonds by infrared, Raman, and X-ray absorption spectroscopies applied in situ in aqueous environment. Aqueous dispersions of nanodiamonds with hydrogenated, carboxylated, hydroxylated, and polyfunctional surface terminations were compared. A different hydrogen bond network was found in hydrogenated nanodiamonds dispersions compared to dispersions of nanodiamonds with other surface terminations. Although no hydrogen bonds are formed between water and hydrogenated surface groups, a long-range disruption of the water hydrogen bond network is evidenced in hydrogenated nanodiamonds dispersion. We propose that this unusual hydration structure results from electron accumulation at the diamond–water interface.

Phone: þ7 495 939 16 53, Fax: þ7 495 939 11 04Interactions of oxidized detonation nanodiamond and carbon dots with protic solvent molecules in suspensions of water, methanol, and isopropyl alcohol were studied by Raman and fluorescence spectroscopy. The structure of the solvent at the interface with nanoparticles and the strength of the hydrogen bonds between the functional groups on the surface of the nanoparticles and the solvent molecules depend on the type of solvent. The molecules of the solvent affect the fluorescent properties of the nanoparticles. It was found that the more intense fluorescence of nanoparticles corresponds to weaker hydrogen bonding between the surface of the carbon nanoparticles and the surrounding molecules of the solvent. The mechanism of mutual influence of the carbon nanoparticles and the solvent on the properties of each other has been suggested.Fluorescence properties of nanodiamonds in the solvents with different hydrogen bonding.

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Efficiency of adsorption of nucleic acid nitrogenous bases (NBs) on carboxylated detonation nanodiamond (DND−COOH) particles in aqueous media at pH = 7.4−7.6 and pH = 13.4 was investigated using Raman spectroscopy and infrared (IR) absorption spectroscopy. A significant difference in the adsorption activity of NDs toward four different individual NBs, guanine, adenine, cytosine, and thymine, had been observed. The highest adsorption activity on DND−COOH was observed for cytosine and, in descending order, for adenine and thymine. At the same time, adsorption activities of the adenine−thymine and guanine−cytosine complementary pairs on nanodiamonds (NDs) were similar. Analysis of the hydrogen bond parameters in the adsorption of complementary pair adenine−thymine on the ND surface had been done using the density functional theory-based molecular modeling. The theoretical calculations are consistent with the experimental results.