Carboxylic acid is a commonly utilized functional group for covalent surface conjugation of carbon nanoparticles that is typically generated by acid oxidation. However, acid oxidation generates additional oxygen containing groups, including epoxides, ketones, aldehydes, lactones, and alcohols. We present a method to specifically enrich the carboxylic acid content on fluorescent nanodiamond (FND) surfaces. Lithium aluminum hydride is used to reduce oxygen containing surface groups to alcohols. The alcohols are then converted to carboxylic acids through a rhodium (II) acetate catalyzed carbene insertion reaction with tert–butyl diazoacetate and subsequent ester cleavage with trifluoroacetic acid. This carboxylic acid enrichment process significantly enhanced nanodiamond homogeneity and improved the efficiency of functionalizing the FND surface. Biotin functionalized fluorescent nanodiamonds were demonstrated to be robust and stable single-molecule fluorescence and optical trapping probes. 相似文献
A procedure for the photochemical chlorination of nanodiamond by molecular chlorine in the liquid phase was proposed. This
process was studied quantitatively for the first time. Hydrolytic stability of the chlorinated nanodiamond surface in air
and in a 0.05 M solution of NaOH was determined. A possibility of disintegration of the initial aggregates (<60 μm) to finer aggregates (<200
nm) was shown. The reactions of a series of C-nucleophiles (organolithium reagents, CN− ion) with the chlorinated surface were carried out.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2130–2137, December, 2006. 相似文献
The effect of different kinds of surfactants on the size distribution of nanodiamond particles in clean oil was studied.Results show that the dispersing stability of nanodiamond modified with surfactangts YS-1 and SB-18 simulta-neously is much better than those modified with either of them because of synergism of the surfactangts.And the particle size distribution in the system can be improved remarkably after the adoption of hyperdispersants such as SA-E and SA-F.Anchoring groups of those hyperdispersants can be bonded with the particle surface by chemical and/or hydrogen bonding and their soluble chains are well compatible with the dispersion media.As a result,the particles are uniformly distrbuted in the system owing to the steric stabilization.A very stable clean-oil based nanodiamond suspension with an average particle size of around 53.2 nm was prepared. 相似文献
The fabrication of nanodiamond (ND)‐based drug carriers for tumor‐targeted drug delivery is described. The ND clusters with an average size of 52.84 nm are fabricated using a simple fluidic device combined with a precipitation method and then conjugated with folic acid (FA) and doxorubicin (Dox) via carbodiimide chemistry to obtain FA/Dox‐modified ND (FA/Dox‐ND) clusters. Cell culture experiments revealed that KB (folate receptor‐positive) cells are preferentially ablated by FA/Dox‐ND clusters compared to A549 (folate receptor‐negative) cells. In vivo results revealed that FA/Dox‐ND clusters are specifically accumulated in tumor tissues after intravenous injection into tumor‐bearing mice, effectively reducing the volume of tumor. Based on these results, this study suggests that FA/Dox‐ND clusters can be a good candidate as tumor‐targeted nanovehicles for delivery of antitumor drug.
The synthesis of a new class of fluorescent carbon nanomaterials, carbon‐dot‐decorated nanodiamonds (CDD‐ND), is reported. These CDD‐NDs are produced by specific acid treatment of detonation soot, forming tiny rounded sp2 carbon species (carbon dots), 1–2 atomic layers thick and 1–2 nm in size, covalently attached to the surface of the detonation diamond nanoparticles. A combination of nanodiamonds bonded with a graphitic phase as a starting material and the application of graphite intercalated acids for oxidation of the graphitic carbon is necessary for the successful production of CDD‐ND. The CDD‐ND photoluminescence (PL) is stable, 20 times more intense than the intrinsic PL of well‐purified NDs and can be tailored by changing the oxidation process parameters. Carbon‐dot‐decorated DNDs are shown to be excellent probes for bioimaging applications and inexpensive additives for PL nanocomposites. 相似文献