long luminescence lifetimes of 1.38 and 0.26 ms, respectively. It was found that the luminescence of [Tb3+(DTTA)] could be quenched by ONOO− rapidly and specifically in aqueous buffers, while that of [Eu3+(DTTA)] did not respond to the addition of ONOO−. Thus, by simply mixing [Eu3+(DTTA)] and [Tb3+(DTTA)] in an aqueous buffer, a ratiometricluminescenceprobe specific for time‐gatedluminescence detection