Imaging by highly stable near-infrared luminescence by single-walled carbon nanotubes
we used single-walled carbon nanotubes (SWNTs) as a tool for high-bandwidth intracellular tracking. SWNTs are stiff quasi–one-dimensional tubular all-carbon nanostructures with diameters of ~1 nm and persistence lengths above 10 μm. Individual semiconducting SWNTs luminesce with large Stokes shifts in the near-infrared (900 to 1400 nm). This window is virtually free of autofluorescence in biological tissues. Fluorescence emission is highly stable with no blinking and negligible photobleaching (, allowing for long-term tracking. The fluorescence lifetime is short [~100 ps ] so that high excitation intensities allow millisecond time resolution.
Fakhri, Nikta, et al. “High-resolution mapping of intracellular fluctuations using carbon nanotubes.” Science 344.6187 (2014): 1031-1035.
New experimental techniques are developed and further developed in our lab, with emphasis on high-resolution microscopy methods and single-molecule manipulation techniques (optical traps, atomic force microscopy), single-molecule fluorescence/spectroscopy techniques and microrheology. For example, we have explained how a first order interference effect makes it possible to detect motions of a particle trapped by an optical trap by monitoring the distribution of light intensity in the back-focal plane of the lens collecting the trapping laser light. Many subtle issues are furthermore involved in calibrating optical traps.
Mizuno, Daisuke, et al. “Nonequilibrium mechanics of active cytoskeletal networks.” Science 315.5810 (2007): 370-373.