An indium tin oxide (ITO) electrode modified with monolayer TiO2/ [Ru(phen)2(dC18bpy)]2+ (phen=1,10-phenanthroline,dC18bpy 4,4’-dioctadecyl-2,2’ bipyridyl) hybrid film (denoted as ITO/TiO2-Ru) has been prepared by the Langmuir-Blodgett (LB) method,and t(h) photodeposition of Pd clusters onto the surface of the hybird film was achieved (denoted as ITO/TiO2-Ru/Pd).Atomic force microscop reveals that the single-layered hybrid film of TiO2 / [Ru(phen)2(dC18bpy)]2+ is closely packed at a surface pressure of 25 mN m-1 and has thickness of 3.20 ± 0.5 nm.X-ray photoelectron spectra shows the formation of Pd nanoparticles on the surface of hybrid film with a radius (o) 20-160 nm.When applied to oxidizing the mononucleotide of guanosine 5’- monophosphate (GMP),a large catalytic oxidative current w(a) achieved on the modified electrodes at the applied potential above 700 mV (vs Ag|AgCl|KCl ) and,more significantly,this response w(a) further enhanced by being deposited Pt nanoclusteres onto the surface of the modified electrode under light irradiation (λ>360nm).Su(c) results may open up a new way for preparing biosensors.