▎ 摘　　要

Highly sensitive methods are important for monitoring the concentration of metal ions in industrial wastewater. Here, we developed a new probe for the determination of metal ions by fluorescence quenching. The probe consists of hydroxylated graphene quantum dots (H-GQDs), prepared from GQDs by electrochemical method followed by surface hydroxylation. It is a non-reactive indicator with high sensitivity and detection limits of 0.01 mu M for Cu2+, 0.005 mu M for Al3+, 0.04 mu M for Fe3+, and 0.02 mu M for Cr3+. In addition, the low biotoxicity and excellent solubility of H-GQDs make them promising for application in wastewater metal ion detection.