ja5b00246_si_001.pdf (3.14 MB)
Development of a Series of Near-Infrared Dark Quenchers Based on Si-rhodamines and Their Application to Fluorescent Probes
journal contribution
posted on 2015-04-15, 00:00 authored by Takuya Myochin, Kenjiro Hanaoka, Shimpei Iwaki, Tasuku Ueno, Toru Komatsu, Takuya Terai, Tetsuo Nagano, Yasuteru UranoNear-infrared (NIR) fluorescent probes
based on the Förster
resonance energy transfer (FRET) mechanism have various practical
advantages, and their molecular design is generally based on the use
of NIR dark quenchers, which are nonfluorescent dyes, as cleavable
FRET acceptors. However, few NIR dark quenchers can quench fluorescence
in the Cy7 region (over 780 nm). Here, we describe Si-rhodamine-based
NIR dark quenchers (SiNQs), which show broad absorption covering this
region. They are nonfluorescent independently of solvent polarity
and pH, probably due to free rotation of the bond between the N atom
and the xanthene moiety. SiNQs can easily be structurally modified
to tune their water-solubility and absorption spectra, enabling flexible
design of appropriate FRET pair for various NIR fluorescent dyes.
To demonstrate the usefulness of SiNQs, we designed and synthesized
a NIR fluorescent probe for matrix metalloproteinase (MMP) activity
using SiNQ780. This probe 1 could detect MMP activity in vitro, in cultured cells and in a tumor-bearing mouse,
in which the tumor was clearly visualized, by NIR fluorescence. We
believe SiNQs will be useful for the development of a wide range of
practical NIR fluorescent probes.