Enhanced live cell membrane imaging using surface plasmon-enhanced total internal reflection fluorescence microscopy

Using a total internal reflection fluorescence microscopy (TIRFM) technique to image live cells on a biosurface not only provides an enhanced understanding of cellular functions, but also improves the signal-to-noise ratio of the images. However, the intensity of the fluorescence signal must be increased if a more dynamic biomolecular imaging capability is required. Accordingly, this study presents a surface plasmon-enhanced TIRFM technique in which the fluorescence signals are enhanced via surface plasmons offered by a silver nanolayer. The developed microscopy technique is successfully applied to the real-time observation of the thrombomodulin proteins of live cell membranes. The experimental results and the simulation results demonstrate that the live cell membrane images obtained in the proposed surface plasmon-enhanced TIRFM technique are brighter by approximately one order of magnitude than those provided by conventional TIRFM.