Ratiometric fluorescent probe based on pyrrole-modified rhodamine 6G hydrazone for the imaging of Cu2+ in lysosomes

A novel rhodamine-based Schiff base derivative was obtained via the simple condensation of substituted formyl-1H-pyrrole and rhodamine 6G hydrazone. Fluorescence resonance energy transfer enabled the subsequent use of the derivative as a naked-eye colorimetric and ratiometric fluorescent sensor for Cu2+ in semi-aqueous solution, and the existence of the morpholine group enabled the further application of the sensor in imaging Cu2+ in the lysosomes of HeLa cells.