A pyrene-based colorimetric and fluorescent pH probe with large stokes shift and its application in bioimaging

Abstract

A pyrene-based colorimetric and fluorescent pH probe with large Stokes shift (145 nm) was developed. PNY afforded a pKa of 2.98 and responded linearly to minor pH changes within the range of 2.43 and 3.71. In addition, PNY could be used for detecting H+ with high sensitivity and selectivity, showing colorimetric and fluorometric dual-modal responses with short response time. Furthermore, PNY had good photostability, excellent reversibility and cell membrane permeability. Significantly, PNY could image acidic pH in A549 cells and visualized extreme acidity in E. coli cells.