1. Department of Chemistry and Center for Frontier Materials and Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan, Institute of Biomedical Engineering, National Taiwan University, Taipei 106, Taiwan, Department of Biomedical Engineering, I-Shou University, Kaohsiung County 840, Taiwan, and Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 106, Taiwan