A novel ratiometric fluorescent probe for detection of Fe3+ by rhodamine–quinoline conjugate

•The probe displayed selectivity toward Fe3+ even coexistent with other metal ions.•FRET, coupled with PET process are proposed to explain the observed spectral.•The detection limit of Fe3+ reached at 8.3 × 10−7 m.

In this study, we have developed a novel ratiometric fluorescence probe (HL) which contains rhodamine and quinoline moiety. In the absence of Fe3+, the sensor displays fluorescence emission at 425 nm, in the presence of Fe3+, the sensor shows a large fluorescence enhancement at 550 nm in methanol. More importantly, the reversibility of the recognition process of HL is performed by adding a Fe3+ bonding agent Na2EDTA.

Graphical abstractUpon addition of Fe3+, the fluorescence of rhodamine (at 550 nm) and quinoline (at 425 nm) enhanced simultaneously. Fluorescence resonance energy transfer process (FRET), coupled with photo induced electron transfer (PET) process are proposed to explain the observed spectral.Figure optionsDownload full-size imageDownload as PowerPoint slide