A smart approach toward rhodamine spiro-ring derivatives sensing platform for lysosome-targetable imaging applications

Abstract

As acidic organelles (pH 4.0–5.5) in living cells, lysosomes play key roles in numerous cellular biological processes, and associate with diverse diseases. Small molecular probes based fluorescence imaging techniques capable of providing information on target analytes in lysosomes are highly appreciated. Herein, for the first time we propose a new strategy of constructing pH-independent rhodamine based spiro-ring platform for lysosomal imaging applications. As a proof of concept, by incorporating lysosome specific moiety morpholine, a thio-lactone rhodamine analogue HN4MS for HOCl with high sensitivity, high selectivity and fast response at lysosomal pH value was developed. Moreover, possessing ability of imaging in lysosome organelles, the new probe was successfully applied to visualize exogenous and endogenous HOCl in living cells and tissues, which verified the present avenue for expansion of organelle targetable imaging tools.