Herein, we developed a near-infrared (NIR) fluorescent probe for mitochondrial staining based on the NIR fluorochrome, silicon-rhodamine. The hydrophobicity of the fluorescent core was systematically modified by conjugation with 10 different commercial amines. The resulting fluorescent compounds exhibited similar photophysical properties but diverse hydrophobicity. We identified the optimal level of hydrophobicity associated with high mitochondrial targeting efficiency. In particular, the SiR-Mito 8 probe provided excellent mitochondrial staining and successfully differentiated the live Hep3B cancer cells from normal L02 cells in vitro.
This work was supported by Basic Research Program (2009-0093826, 2016R1E1A1A01941213 and 2016R1C1B2014699) through the National Research Foundation of Korea (NRF) funded by the Korean Government (Ministry of Science and ICT) and by the Ajou University research fund.
