A compound represented by the formula (I) (one of substituents represented by R1 is a trapping group for an object substance for measurement; R2 and R3 represent hydrogen, alkyl, or halogen; R4 and R5 represent alkyl or aryl; R6 and R7 represent hydrogen, alkyl, or halogen; R8 represents hydrogen, alkylcarbonyl, or alkylcarbonyloxymethyl, and X represents silicon, germanium, or tin, which can be used as a fluorescent probe that enables red color bioimaging using intramolecular photoinduced electron transfer.
We see red (and yellow and green): Probe 1 was developed for the visualization of cytoplasmic Ca2+, a pivotal second messenger in many biological responses. The new probe is suitable for multicolor imaging for the simultaneous detection of metal ions or proteins and is superior to the existing redfluorescentprobe Rhod‐2 for the monitoring of cytoplasmic Ca2+ oscillation in cultured cells (see fluorescence