A new crosslinkable light sensitizer, Ru(2,2'-bipyridine-4,4'-bicarboxylic acid) (4,4'-bis(11-dodecenyl)-2,2'-bipyridine)(NCS)(2), denoted as Ru-C for titanium oxide nanocrystalline-based solar cells was synthesized with its crosslinking properties invesitigated by Fourier-transform infrared and UV-vis absorption spectroscopies. After crosslinking by itself or copolymerizing with methyacrylic acid, their sensitized solar cells with poly(methylacrylate)-gelled electrolyte system not only attained more than 5% of power conversion efficiency at AM 1.5 illumination (100 mW/cm(2)), but also gave rise to long storage life. To the best our knowledge, this is the first crosslinkable dye ever applied to the DSSC in the literature. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 366-372, 2010