A unique rectilinearly π-extended rhodamine dye with large Stokes shift and near-infrared fluorescence for bioimaging

A NIR rhodamine fluorophore, TJ730, with a large Stokes shift over 110 nm has been developed. Using the dye as a platform, we have prepared two novel NIR probes for the detection of Cu²⁺ as well as for cytoplasmic and lysosomal Cu²⁺ imaging in living cells.