Manipulation and Bioimaging Applications of Fluorescent Nanodiamonds
Date Issued
2014
Date
2014
Author(s)
Tzeng, Yan-Kai
Abstract
Diamond is an allotrope of carbon. A unique property that distinguishes it from other carbon materials is that diamond is optically transparent and often contains point defects as color centers. Negatively charged nitrogen-vacancy (NV−) defects are the most noteworthy color centers in diamond because it emits far-red fluorescence with high photostability. This unique optical property combined with good biocompatibility makes nanoscale diamonds a promising fluorescent probe for bioimaging, particularly cell tracking studies. Firstly, we measured the efficiency of Forster resonance energy transfer (FRET) with sub-20-nm fluorescent nanodiamonds (FNDs) as the FRET donors and near-infrared dyes as the acceptors. A FRET efficiency of ~7% was found. Next, we built a super-resolution stimulated emission depletion (STED) microscopy system for FNDs and demonstrated the nanoscale precision for fluorescence imaging. FND is an ideal candidate for STED, since it does not photobleach. In contrast, organic dyes or fluorescent proteins are easily photodamaged by the high-power STED laser beam. Another distinct feature of FND is that its fluorescence lifetime is more than 13 ns, significantly longer than that of common organic dyes or green fluorescent proteins (GFPs) as well as cell auto-fluorescence. Using a time-gating technique, which successfully reduces cell and tissue auto-fluorescence background signals, we applied FNDs as long-term cell trackers and demonstrated the homing and engraftment capacity of lung stem cells transplanted in mice. Finally, the NV− center in diamond is a very unique quantum system, and can be manipulated by optical detected magnetic resonance (ODMR), a technique applicable to measure environmental changes such as temperature shifts. With the ODMR technique, we achieved high-sensitivity detection of the surrounding temperature of 100-nm FND particles at the nanoscale. All the experimental results demonstrate that FNDs are ideal candidates for potential applications in modern biomedical science and biotechnologies as nanotechnology-enabled imaging agents and sensors.
Subjects
螢光奈米鑽石
螢光共振能量轉移
受激發射損耗顯微術
螢光生命週期影像顯微術
幹細胞
光偵測磁共振技術
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-103-D97223104-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):d7705a374b74aa13d2c68026136a7686