1. School of Dentistry and Graduate Institute of Clinical Dentistry, National Taiwan University and National Taiwan University Hospital, No. 1, Chang-Te Street, Taipei 10016, Taiwan;
2. Department of Chemistry, National Cheng-Kung University, No. 1, University Road, Tainan 701, Taiwan; and
3. Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei, Taiwan