FRET based selective and ratiometric detection of Al(iii) with live-cell imaging

Abstract

A new FRET-based carbazole rhodamine hybrid (CRH) ratiometric fluorescent sensor is reported for the selective detection of Al³⁺. The design of the probe involved two parts: a carbazole hydrazone energy donor and a rhodamine spirolactone unit (potential rhodamine monoanion energy receptor). First, the emission of the carbazole chromophore (“donor” moiety) and next the absorption of the ring-opened rhodamine dye were measured, which clearly showed the overlap between these two spectra, indicating the FRET from the carbazole chromophore to the rhodamine moiety. FRET based ratiometric live-cell imaging for Al³⁺ has been rarely reported. Successful live cell imaging is demonstrated, where on addition of Al³⁺ solution (20 μL), the color of the CRH (20 μL) treated cells changed from blue to red.