A cell-membrane-permeable europium complex as an efficient luminescent probe for singlet oxygen

A unique cell-membrane-permeable europium complex has been developed as a probe for time-gated luminescence detection of singlet oxygen (O-1(2)). Combined with the time-gated luminescence imaging technique, the probe was successfully used for investigating the time-dependent generation and distribution of O-1(2) induced by the clinical drugs of photodynamic therapy in cancer cells.