Squaraine as a bright, stable and environment-sensitive far-red label for receptor-specific cellular imaging

Abstract

Herein, we show that a far-red arylidene–squaraine dye is stable against nucleophiles, in contrast to arene–squaraines. Owing to the fluorescence enhancement in apolar media together with high brightness and photostability, this dye was successfully applied to detect the oxytocin G protein-coupled receptor and monitor its internalization in living cells.