FRET-based fluorescence ratiometric and colorimetric sensor to discriminate Fe3+ from Fe2+

Abstract

A benzothiazole conjugated quinoline derivative appended with rhodamine-6G acts as an efficient FRET-based single molecular switch for Fe³⁺. The structure of the probe was confirmed through its single crystal X-ray study. The sensor demonstrates an immediate fluorescence ratiometric response specific towards Fe³⁺ which also allows facile naked-eye detection of Fe³⁺. The probe is highly selective only towards Fe³⁺ in comparison to other environmentally important cations, including Fe²⁺. Moreover, the detection limit was found to be in the 10⁻⁸ M range for the recognition of Fe³⁺.