One-pot fabrication of boric acid assisted N-doped CDs and advanced fluorescence sensing property from yellow to red for Fe3+ in acidic water environment

Iron is one very important element, which plays key roles in living organisms. Especially, ferric iron ions participate in various biochemical processes of the body through functions such as heme synthesis, immune regulation, iron utilization and transport, redox reactions, and gene expression regulation. Herein, a highly selective fluorescence sensor for ferric ion based on boric acid assisted N-doped CDs was prepared. In the sensing process of Fe 3+ , the fluorescence of BA-N-CDs water solution changes from yellow to red obviously in acidic condition, accompanied by the change in color of the solution from pale yellow to dark red. In addition, the fluorescence sensor shows low detecting limit (nanomolar level) by fluorescence titration spectrum. Moreover, according to evaluate excellent fluorescence imaging of sensor toward Fe 3+ in M109 cell and tomato leaf, the study provided an important idea for constructing water-soluble fluorescence sensor for Fe 3+ in organism and plant system.