Development of a novel fluorescence probe capable of assessing the cytoplasmic entry of siderophore-based conjugates.

A novel fluorescence probe capable of assessing the cytoplasmic entry of siderophore-based conjugates was synthesized and evaluated by photochemical characterization and cell-based assays. The specific responsiveness to the cytoplasmic entry of the probe was implemented by adopting a disulfide linker, whose cleavage under the reducing conditions of the cytoplasm induced the display of a distinctive fluorescence signal.