Water-soluble pyrrolopyrrole cyanine (PPCy) near-infrared fluorescent pH indicators for strong acidity

Abstract

Water-soluble, fluorescence-switchable derivatives of pyrrolopyrrole cyanines (PPCys) which serve as near-infrared pH indicators have been synthesized. The dyes reported have pKa values of 2.4-3.4 and thus are suitable for sensing in highly acidic environments. The new pH probes were evaluated by fluorescence imaging experiments in a cellular environment. This journal is