Rapid detection of nerve agents in environmental and biological samples using a fluorescent probe.

Nerve agents are highly toxic chemical warfare agents that are easy to synthesize and have recently been applied many times in local wars and terrorist attacks. Fluorescent probes have been widely used in life science and medical research due to their features of short reaction time, high sensitivity and good selectivity. Herein, two fluorescent compounds, NMU-1 and NMU-2, were synthesized for the selective detection of nerve agents. NMU-1 exhibited good detection performance for nerve agents. With increasing nerve agent concentration, the fluorescence signal of NMU-1 at 498 nm gradually decreased with an excellent linear relationship. NMU-1 exhibited a low LOD (4.6 µM for DCP and 8.41 µM for soman), a rapid response (less than 3 min) and a large Stokes shift (98 nm) along with obvious color changes. Due to its high sensitivity and good selectivity, NMU-1 was successfully applied to image nerve agents in living PC12 cells. Furthermore, NMU-1 was used as a key element to develop chemical warfare agent test paper, which exhibited significant fluorescent changes under hand-held 365-nm UV light upon contact with nerve agents.

Effect of exogenous hydrogen sulfide on gastric acid secretion.

BACKGROUND AND AIM: H2 S is an important gasotransmitter in the gastrointestinal tract. The aim of the present study was to investigate the effect of exogenous H2 S on gastric acid secretion. METHODS: Male Wistar rats were randomly divided into physiological saline (PS) group, sodium hydrosulfide (NaHS; 50, 100, and 150 µmol/kg body weight) group, glibenclamide + NaHS group, and SQ22536 + NaHS group. PH of gastric juice before injection and after injection were determined by a PH meter. RESULTS: The results showed that NaHS, an exogenous H2 S donor, injected into the enterocoelia significantly reduced the PH of gastric juice, the same volume of PS administered similarly did not change PH of gastric juice, the promotional effect of NaHS on gastric acid secretion could be abolished by glibenclamide, an ATP-sensitive potassium channel K(ATP) blocker SQ22536, an inhibitor of adenyl cyclase. CONCLUSIONS: The data from these experiments suggest that exogenous H2 S promoted gastric acid secretion, which may occur via K(ATP) channels and activate AC-cAMP pathway.