A Rapid Near-Infrared Fluorescent Probe for Cysteine Based on Isophorone and its Application in B16 Cell Imaging.

A novel near-infrared fluorescent probe SWJT-5 based on dicyanoisophorone was synthesized. It achieved the rapid (within 40 s) and discriminative detection of Cys over Hcy and GSH with a large Stokes shift (205 nm). It showed high selectivity and sensitivity for Cys, and had an obvious enhancement of fluorescence emission. The detection limit was 0.43 µM. This probe also had low background interference and little damage to biological samples. Therefore, SWJT-5 had been applied to bioimaging in living cells successfully.