In this study, radiolytic functionalization of fullerene in methanol/1,2-dichlorobenzene mixtures and its applications with respect to biosensor support materials were studied. To obtain supports for biosensors for electron transfer, fullerene was functionalized by gamma-irradiation in a methanol/1,2-dichlorobenzene mixture solution. The hydroxyl group-modified fullerene, F-fullerene, was characterized by Fourier-transform infrared, Raman spectroscopy, MALDI-TOF mass spectroscopy, and elemental analysis. As a result, the main hydroxyl group was successfully introduced on the surface of fullerene. F-fullerene was found to disperse well in water by ultrasonication. The results indicated that F-fullerene is a good candidate for use in biological systems as a biosensor support material. A biosensor based on F-fullerene was prepared by hand-casting the mixture of tyrosinase, F-fullerene, and 2% chitosan solution on an ITO electrode. Furthermore, the prepared biosensor was optimized pH and temperature. The prepared biosensor was then evaluated for its ability to analyze phenolic compounds contained in commercial red wines. The total phenolic concentration was determined to be in the range of 397-895 mg/L. From these results, the electron transfer ability of F-fullerene was improved on an enzyme biosensor. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1785-1791, 2011