A novel water-soluble silicon compound was synthesized by the reaction between tetraethoxysilane (TEOS) and propylene glycol. This compound is stable in aqueous solutions and miscible with water in any ratio. The potential of this new silicon reagent for synthesis of multicomponent silicate by solution based techniques was evaluated by preparation of the (Y,Ce,Gd)₂SiO₅ blue emission phosphor using a polymerizable complex method. Phase compositions and fluorescence properties of the prepared material was compared against reference samples prepared by either conventional solid state reaction or by a polymerizable complex method employing the other silicon reagents. It was revealed the application of new water-soluble silicon compound as a reagent for synthesis resulted in the formation of a single phase (Y,Ce,Gd)₂SiO₅ material at reduced temperatures and its fluorescence intensity considerably outperformed those of the phosphors prepared by the other methods in this work.