CARBON NANOPARTICLES AND METHOD OF THEIR PRODUCTION Russian patent published in 2025 - IPC C01B32/15 C09K11/65 C09K11/78 B82B1/00 B82B3/00 B82Y15/00 B82Y40/00 A61K49/06 

FIELD: chemistry.

SUBSTANCE: invention can be used in medicine and biology for multimodal analysis of images of biological objects, including living tissue, using luminescent spectroscopy and magnetic resonance imaging. Carbon nanoparticles with size of 1-18 nm, consisting of carbon, oxygen, nitrogen and a metal, are obtained through formation thereof from precursors: formamide, citric acid and metal salts, represented by gadolinium chloride or nitrate, with molar ratio of formamide to citric acid and to said gadolinium salt equal to 19:1:(0.01-0.05). Precursors are mixed for 5 minutes under the effect of ultrasound until complete dissolution. Obtained mixture is transferred into a closed reaction vessel, heated for 8 hours at 180 °C for a solvothermal reaction, followed by cooling, dissolved in alcohol and centrifuged to separate precipitate for 15 minutes at 6000 rpm. Supernatant is removed, and the precipitate is dissolved again in alcohol and centrifuged with separating the precipitate and removing the newly formed supernatant. These operations are repeated many times and stopped when the supernatant acquires a light violet or yellow hue. Then the precipitate is dialysed against distilled or deionised water in a dialysis bag with cutoff molecular weight 3.5 kDa with water replacement according to its colouring for several days. After dialysis, the carbon nanoparticles are dissolved in water and the precipitate is separated again with the same centrifugation parameters. Precipitate is dried by lyophilisation to obtain dark powder of carbon nanoparticles, having the property of photoluminescent imaging of biological objects and reducing proton relaxation time during magnetic resonance imaging thereof, having the following composition, at least %: 59.8-59.9 of carbon; 20.5-21.4 of oxygen; 18.1-19.1 of nitrogen and 0.5-0.7 of gadolinium.

EFFECT: obtained carbon nanoparticles have long-wavelength radiation with a maximum of the photoluminescence band of 600-650 nm when excited with radiation with wavelength of 550-600 nm, as well as quantum yield of photoluminescence of 35-41 %.

4 cl, 1 tbl, 2 ex