A NIR fluorescent sensor for biothiols based on dicyanoisophorone derivative with large Stokes shift and high quantum yield
Herein, a NIR fluorescent probe N-Bio was developed for effective detection of biothiols by exploiting dicyanoisophorone derivative (N-OH) as the fluorophore and thiols-responsive 2,4-dinitro-benzenesulfonyl (DNBS) group as the recognition group. The introduction of N-OH fluorophore endowed the probe with high quantum yield (0.30), large Stokes shift (120 nm), excellent photostability and high NIR fluorescence brightness inside cells. Upon the cleavage of the DNBS group by biothiols, probe N-Bio demonstrated rapid response (6 min for Cys, 12min for GSH and 14 min for Hcy), high signal to noise ratios (208-fold for Cys, 204-fold for GSH and 168-fold for Hcy) and exceedingly low detection limit (36.93 nM for Cys, 32.56 nM for GSH, 65.03 nM for Hcy). Encouraged by the appreciable sensing performance in vitro, N-Bio was then successfully applied for real-time monitoring the level of biothiols in living cells and real sample detection.