A novel ICT-based two photon and NIR fluorescent probe for labile Fe2+ detection and cell imaging in living cells

[Display omitted] •A new N-oxide based and turn on fluorescent probe for Fe2+ was developed.•The probe possessed a high selectivity for Fe2+ among various biologically relevant species and fast rapid response.•Monitoring Fe2+ with TPM fluorescence imaging for the first time. Iron is an essential element for human body, involved in important biochemical processes in the body, especially in biological oxidation. Misregulation of iron levels in the cell is concerned with serious diseases. Here, a novel two photon and turn on NIR-fluorescent probe based ICT for detection of Fe2+ is first reported. The probe exhibited brilliant selectivity and excellent sensitivity (DL = 4.5 μM), rapid response (15 min) and “naked-eye colorimetric sensor” for monitoring of Fe2+. More importantly, the probe was successfully applied to real-time monitor Fe2+ in living cell through two-photon microscopy fluorescence imaging with excitation 680 nm.