A new rhodamine fluorescent OFF-ON-OFF probe for selective sensing of Fe3+ and AcO- in aqueous media and living cells

A new fluorescent chemosensor for Fe3+ was developed based on a rhodamine platform. L displayed highly selective and sensitive “OFF-ON” fluorescence response and naked-eye color change to Fe3+ in aqueous solution. The resulting L-Fe3+ complex was found to act as a selective“ ON-OFF” fluorescence probe for AcO- against common anions and cations with a Fe3+ displacement approach. The detection limits of L to Fe3+ and L-Fe3+ complex to AcO- were estimated to be 6.04×10-8 mol/L and 7.51×10-8 mol/L, respectively. The good biocompatibility of L enabled the investigation of fluorescent response for Fe3+ and AcO- in living Ana-1 cells by confocal microscope.