▎ 摘　　要

Ratiometric fluorescent probes are of great importance in research, because a built-in correction for environmental effects can be provided to reduce background interference. However, the traditional ratiometric fluorescent probes require two luminescent materials with different emission bands. Herein a novel ratiometric probe based on a single-wavelength-emitting material is reported. The probe works by regulating the luminescent property of graphene quantum dots with UV illumination as activator. The ratiometric sensor shows high sensitivity and specificity for iron ions. Moreover, the ratiometric sensor was successfully employed to monitor ferritin levels in Sprague Dawley rats with chemical-induced acute liver damage. The proposed single-wavelength ratiometric fluorescent probe may greatly broaden the applicability of ratiometric sensors in diagnostic devices, medical applications, and analytical chemistry.