The rational design of a highly sensitive and selective fluorogenic probe for detecting nitric oxide

Abstract

A rationally designed small-molecule fluorogenic probe for nitric oxide (NO) detection based on a new switching mechanism has been developed. Attaching a NO-responsive dihydropyridine pendant group to a fluorophore led to a probe that displays a very high sensitivity to NO concentrations down to the low nM range and a very high specificity to NO while being insensitive to other oxidative oxygen/nitrogen species that often interfere with the sensing of NO.

Water-soluble Hantzsch ester as switch-on fluorescent probe for efficiently detecting nitric oxide

“…On the contrary, compound PYS is highly luminescent with a dramatically boosted Φ F (46.5%). The spectra here are very similar to those of the probe we reported previously [37]. On the account of the quantitatively NO-induced conversion of Hantzsch ester into the pyridine form, the enlargement of the fluorescence herein inspired us to utilize the compound DHPS as effective NO fluorescent probe.…”

“…In addition, a linear relationship between the fluorescent intensity and the concentrations of NO was deduced with a correction coefficient of 0.998. Meanwhile, the calculated lowest limit detection (LOD, 3 σ/slope) was determined to be about 18 nM, which is similar with the values in literatures [37,42,45,46], suggesting that probe DHPS is a highly sensitive agent for detecting NO.…”

“…6, the unstimulated cells showed almost no fluorescence while it presented evidently dark blue fluorescence emission in the stimulated cells, suggesting that endogenously generated LPS-stimulated NO could be captured by probe DHPS in intracellular environments. Due to the improvement of its water solubility, the necessary dosage of probe DHPS for capturing the endogenously generated NO was only half the amount of our previously reported NO probe [37].…”

“…However, this developed strategy still has its limitations as follows: (i) Self-oxidation-sensitive electron-abundant o-phenylenediamine groups makes it easily react with other reactive oxygen/nitrogen species, lighting up its fluorescence and interfering with the sensing process of NO; (ii) oxidized species rather than NO itself are demanded to react with the vicinal aromatic diamines [1,35,36]. To solve those problems, our group recently reported a highly selective fluorogenic probe for NO sensing based on the Hantzsch ester [37]. As well known, Hantzsch ester is able to quantitatively react with NO to give the corresponding pyridine, a reaction that is independent of oxygen [38,39].…”

A fast and selective two-photon phosphorescent probe for the imaging of nitric oxide in mitochondria

“…The merged images of complexes co-stained with the mitochondria tracker green displayed high co-localization overlap with a 0.85 coefficient. Moreover, as a control to eliminate unpredictable factors that may cause background fluorescence, cells were pre-treated with L-NMA [56] which is an inhibitor for nitric oxide synthase. Fig.…”