National Creative Research Initiative Center for Integrated Optofluidic Systems and Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea, Nano-Bio System Research Team, Seoul Center, Korea Basic Science Institute, Seoul 136-713, Korea, and Small Business Corporation, 24-3, Yoido-dong, Youngdungpo-gu, Seoul 150-718, Korea(At 2007-10-18)
