A novel NIR fluorescent probe with ratiometric imaging of cysteine in endoplasmic reticulum

Abstract

As a significant organelle in cells, endoplasmic reticulum is a cystic, vesicular and tubular structure formed by a single unit membrane. Herein, we develop an endoplasmic reticulum (ER)-targeting NIR probe, HL-Cys, for Cys, which has ratiometrically fluctuating UV-vis absorption and fluorescence spectra with large Stokes shift, with desirable selectivity and sensitivity. Biological imaging demonstrates that HL-Cys could locate in the ER and image Cys levels during ER oxidative stress in HeLa cells.