A highly selective “off-on” fluorescent sensor for subcellular visualization of labile iron(III) in living cells

A fluorescent chemosensor RhHPA showed high selectivity and reversible turn-on response towards the detection of Fe3+, responding rapidly upon the alteration of Fe3+ levels and detecting endogenous chelatable Fe3+ in live bovine aortic endothelial cells, with two Fe3+ pools being located in mitochondria and endosomes/lysosomes for the first time.167