A novel structurally modified isophorone fluorescent probe for H2S detection.

Hydrogen sulfide (H2S) has a comprehensive contribution to the normal operation and stability of organisms and is also present in environmental water samples and food deterioration. Thus, it is exceedingly promising and significant to develop a highly sensitive detection technique for tracing H2S. Inspired by this, we designed and synthesized a new fluorescent probe 2-[3-[2-[3-bromo-4-(2,4- dinitrobenzenesulfonate)] ethenyl]-5,5-dimethyl-2-cyclohexen-1-ylidene]propanedinitrile (SP-Br) for hydrosulfide ion detection by introducing bromine atom. Compared with reported H2S probes based on the same fluorescent parent, SP-Br has longer fluorescence emission (λem = 670 nm), shorter response time (3 min), lower detection limit (149 nM), and wider detection range (0-30 nM). SP-Br can emit weak yellow fluorescence, and the emission intensity at 670 nm is considerably enhanced in the presence of hydrosulfide ions. The identification mechanism of hydrosulfide ion by SP-Br was verified by high-resolution mass spectrometry, fluorescence, and UV-vis absorption spectroscopy. In addition, SP-Br has been successfully applied to the monitoring of actual water samples and beer samples and has certain development prospects and value in the fields of environmental pollution and food quality analysis.

Rational design of a fluorescent probe for specific sensing of hydrogen peroxide/glucose and intracellular imaging applications.

A new type of dye with advantages of high selectivity and sensitivity is formed by using the strategy of hybridization between the luminescent unit and recognition unit. Based on this strategy, we exploit a novel dye bonding the benzopyrylium salt as a luminescent unit and phenylboronate group as a response site, which is served as a fluorescent probe 1 for specific recognition of hydrogen peroxide in biological application. Probe 1 employs a unique recognition switch, phenylboronate unit, to"turn-on"a highly specific and rapid fluorescence response toward hydrogen peroxide combined with the 1,6-rearrangement elimination reaction strategy. Meanwhile, probe 1 has the ability to glucose assay by taking advantage of glucose oxidase/glucose enzymatic reaction. What's more, the probe 1 is capable of tracking endogenous hydrogen peroxide in living cells and intracellular imaging. Therefore, the newly developed bioprobe 1 is expected to be used to monitor hydrogen peroxide and glucose levels in complex organisms.