1. Center for Nanoparticle Research; Institute for Basic Science (IBS); Seoul 151-742 Republic of Korea
2. School of Chemical and Biological Engineering; Seoul National University; Seoul 151-742 Republic of Korea
3. MC10 Inc., 9 Camp St. Cambridge MA 02140 USA
4. Research Laboratory of Electronics; Massachusetts Institute of Technology; 77 Massachusetts Ave. Cambridge MA 02139 USA