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High-Contrast Reversible Fluorescence Photoswitching of Dye-Crosslinked Dendritic Nanoclusters in Living Vertebrates


  • We are grateful to Dr. Haijun Yao at the Mass Spectrometry Laboratory of the University of Illinois for collecting MALDI spectra of our dendrimer samples. We thank Drs. Kang Taek Lee and Sang Hwan Nam for the measurement of the photobleaching rate, Dr. Nyeon-Sik Eum, Chijung Yun, and Dr. Nam Woong Song for the assistance with the installation of optical equipments, and Prof. Dr. Joon Kim for allowing us to use the DeltaVision imaging system. This work was supported by the National Research Foundation of Korea (2010-0008056, 2010-0002205) funded by the Ministry of Education, Science and Technology and the KRIBB Research Initiative Program.


original image

Dendrimers crosslinked with a photochromic diarylethene (blue in picture) were labeled with the fluorescent dye Cy3 (red) for reversible fluorescence photoswitching. If the obtained nanoclusters are irradiated with UV light, the Cy3 fluorescence is quenched by the diarylethene in its ring-closed form, whereas upon irradiation with visible light, the nanoclusters show fluorescence. High-contrast fluorescence imaging was achieved inside a living zebrafish.