Scanning total internal reflection fluorescence microscopy

摘要

We report on a new form of total internal reflection fluorescence microscopy. Instead of using a prism, an objective of numerical aperture 1.65 is used under ring beam illumination. As a result, the propagating component of the illumination wave is suppressed and a focused evanescent spot is produced with strength of 20 times stronger than that in the prism. A near-field image is obtained by the scanning of a sample illuminated by the evanescent focal spot. The new imaging system has been successfully used for characterising CdSe quantum dot nanoparticles and will be useful in nano-fabrication and single-molecular detection.