A cyanobenzo[a]phenoxazine-based near infrared lysosome-tracker for in cellulo imaging

Abstract

A cyanobenzo[a]phenoxazine-based pH probe with pK_a = 5.0 exhibits OFF–ON emission at 625–850 nm upon excitation at 600 nm in aqueous buffers. The in cellulo imaging experiments with HeLa cells indicate that the probe can serve as a lysosome-specific probe under red light excitation (633 nm) with near infrared emission (650–790 nm).