Bioorthogonal fluorescent nanodiamonds for continuous long-term imaging and tracking of membrane proteins - PUBLICATIONS

Real-time tracking of membrane proteins is essential to gain an in-depth understanding of their dynamics on cell surface. However, con-ventional fluorescence imaging with molecular probes like organic dyes and fluorescent proteins often suffers from photobleaching of the fluorophores, thus hindering their use for continuous long-term observations. With the availability of fluorescent nanodiamonds (FNDs), which have superb biocompatibility and excellent photostability, it is now possible to conduct the imaging in both short and long terms with high temporal and spatial resolution. To realize the concept, we have developed a facile method (e.g., one-pot preparation) to produce alkyne-functionalized hyperbranched-polyglycerol-coated FNDs for bioorthogonal labelling of azide-modified membrane proteins and azide-modified antibodies of membrane proteins. The high specificity of this labelling method has allowed us to continuously monitor the movements of the proteins of interest (such as integrin α5) on/in living cells over 2 h. The results open a new horizon for live cell imaging with functional nanoparticles and fluorescence microscopy.