A novel near-infrared “turn-on” fluorescent probe for selective detection of Fe3+ and its application in vitro imaging

A novel near-infrared fluorescent probe RHCC was devised and synthesized. It exhibits high specificity to Fe 3+ compared to other metals in aqueous solutions. The detection limit of RHCC was 1.2 × 10 −7 M and the complexation stability constant was 5.807 × 10 4 M −1 . The binding ratio of RHCC and Fe 3+ was 1:1 which was measured through MS, FTIR and Job's plot. The energy gap between HOMO and LUMO of RHCC was 3.22 eV, while RHCC- Fe 3+ complex was 0.95 eV. This result means the binding of probe RHCC and Fe 3+ lowers the RHCC- Fe 3+ complex's energy gap and makes it more stable. What's more, in living cells and zebrafishes studies, probe RHCC was no significant cytotoxic effect, indicating it could monitor Fe 3+ in biological system.