Synthesis and Reactions of 2,2-[60]Fullerenoalkanoyl Chlorides

Enantioselective analysis of D- and l- Serine on a layer-by-layer imprinted electrochemical sensor

The present work describes a new, simple, and easy method of generating acrylamide functionalised reduced graphene oxide-fullerene layer-by-layer assembled dual imprinted polymers to quantify D- and L-Serine at ultra trace level in aqueous and real samples. Herein, the pencil graphite electrode was initially spin coated with D-Serine imprinted acrylamide functionalized reduced graphene oxide. After 10 min thermal treatment (50 °C), this electrode was again modified with L-Serine imprinted acrylamide functionalized fullerene molecules. This bilayer assembly was finally made thermally stable by 60 °C exposure for 3 h. The proposed sensor showed better electronic properties with an improved synergism. We have compared this modified electrode with other modified pencil graphite electrodes like single layered acrylamide functionalised reduced graphene oxide or fullerene, single layered acrylamide functionalised reduced graphene oxide-fullerene composite and double layered acrylamide functionalised reduced graphene oxide or fullerene molecules, which yielded very inferior sensitivity due to possible agglomeration and decreased synergism. The chosen system demonstrated a very good analytical figures of merit with differential pulse anodic stripping voltammetry and cyclic voltammetry transduction, showing lower limits of detection (0.24 ng mL^-1, S/N = 3) for both isomers. The proposed sensor assures practical applications as disease biomarker, manifesting several diseases at very ultra-trace level.

Efficient singlet oxygen generation from sugar pendant C60 derivatives for photodynamic therapy

Glc-pendant C₆₀ compounds exhibited high photocytotoxicity against HeLa cells due to the more efficient singlet oxygen generation as compared with that of Glc-pendant azafulleroids.

Conformational analysis of single perfluoroalkyl chains by single-molecule real-time transmission electron microscopic imaging

Whereas a statistical average of molecular ensembles has been the conventional source of information on molecular structures, atomic resolution movies of single organic molecules obtained by single-molecule real-time transmission electron microscopy have recently emerged as a new tool to study the time evolution of the structures of individual molecules. The present work describes a proof-of-principle study of the determination of the conformation of each C-C bond in single perfluoroalkyl fullerene molecules encapsulated in a single-walled carbon nanotube (CNT) as well as those attached to the outer surface of a carbon nanohorn (CNH). Analysis of 82 individual molecules in CNTs under a 120 kV electron beam indicated that 6% of the CF2-CF2 bonds and about 20% of the CH2-CH2 bonds in the corresponding hydrocarbon analogue are in the gauche conformation. This comparison qualitatively matches the known conformational data based on time- and molecular-average as determined for ensembles. The transmission electron microscopy images also showed that the molecules entered the CNTs predominantly in one orientation. The molecules attached on a CNH surface moved more freely and exhibited more diverse conformation than those in a CNT, suggesting the potential applicability of this method for the determination of the dynamic shape of flexible molecules and of detailed conformations. We observed little sign of any decomposition of the specimen molecules, at least up to 10(7) e·nm(-2) (electrons/nm(2)) at 120 kV acceleration voltage. Decomposition of CNHs under irradiation with a 300 kV electron beam was suppressed by cooling to 77 K, suggesting that the decomposition is a chemical process. Several lines of evidence suggest that the graphitic substrate and the attached molecules are very cold.

Synthesis of PEGylated fullerene-5-fluorouracil conjugates to enhance the antitumor effect of 5-fluorouracil

Many drugs have been delivered by different types of nanoscale vehicles to enhance their therapeutic efficacy. 5-Fluorouracil (5FU) is a widely used antitumor drug, however its bioavailability still needs to be improved. Herein we synthesized a polyethylene glycol monomethylether-C(60)-5FU conjugate (mPEG-C(60)-5FU) and evaluated its antitumor efficacy in vitro. The results show that the inhibition abilities of mPEG-C(60)-5FU to the human breast cancer cell line MCF-7 and the human gastric carcinoma cell line BGC-823 are significantly higher than that of 5FU. The conjugate has good stability in murine serum for at least 24 h. Moreover, the PEGylated fullerene (mPEG-C(60)) vehicle is non-toxic to MCF-7 cells. These results demonstrate that mPEG-C(60) is an efficient vehicle for the delivery of 5FU.

15N-labeled ionic probe attachment mass spectrometry of carbon clusters

An ionization method that uses metal-complex-based ionization probes, malonic acid 3-[2,6-bis(4,4-dimethyloxazolin-2-yl)pyridin-4-yloxy]propyl ethyl ester (EM-TMpybox) and potassium N-{3-[2,6-bis(4,4-dimethyloxazolin-2-yl)pyridine-4-yloxy]propyl} aminoacetate (Sar-TMpybox), was developed for isotope ratio analysis and the effective ionization of unsubstituted carbon clusters. The preparation of Sar-TMpybox and EM-TMpybox and their applications in cold-spray ionization mass spectrometry are reported. A probe applicable to a substituted fullerene is also demonstrated.

Toward Controlled Spacing in One-Dimensional Molecular Chains: Alkyl-Chain-Functionalized Fullerenes in Carbon Nanotubes

A range of fullerenes (C60) functionalized with long alkyl chains have been synthesized and inserted into single-walled carbon nanotubes. The impact of the alkyl chain length and of the type of linker between the addend and the fullerene cage on the geometry of molecular arrays in nanotube has been studied by high-resolution transmission electron microscopy. In the presence of functional groups the mean interfullerene separations are significantly increased by 2-8 nm depending on the length of the alkyl chain, but the periodicity of the fullerene arrays is disrupted due to the conformational flexibility of the alkyl groups.