Rational design of biotinylated probes: fluorescent turn-on detection of (strept)avidin and bioimaging in cancer cells

Two fluorescent probes SPS1 and SPS2 were designed by connecting biotin to an environment-sensitive coumarin fluorophore. Streptavidin and avidin induced dramatical fluorescence changes in both probes. SPS2 has potential in fluorescent imaging of biotin receptor-enriched tumor cells.