A rhodamine derivative as a lock and SCN- as a key: visible light excitable SCN- sensing in living cells

A visible light excitable rhodamine based probe operates as a SCN- selective fluorescent turn-on sensor for living cell imaging with a detection limit of 0.01 mu M, which is much lower than the normal SCN- level in the human body. A lock and key model has been proposed to explain the fluorescence enhancement of the rhodamine probe in the presence of SCN-.