A novel far-red fluorescence bioimaging probe based on rhodamine 101 derivative for Cu2+ with high sensitivity and selectivity

A novel rhodamine 101 derivative has been synthesized and employed as a fluorescent off-on probe for monitoring Cu2+ in aqueous solutions and living cells. Under physiological conditions, it exhibits a remarkable increase in absorbance at 587 nm and an enhanced fluorescence at 615 nm toward Cu2+ in a highly sensitive, selective and rapid manner. The probe can be applied to the quantification of Cu2+ with a linear concentration range covering from 0.4 M to 16 M ( R-2 = 0.9955) and a detection limit of 40 nM. Furthermore, the proposed probe has been successfully applied for fluorescence imaging of Cu2+ in living cells.