Design,Synthesis And Application Study Of Novel Fluorescent Probes For Hydrogen Sulfide In Food, As Well As Sulfur Dioxide In Nucleus

Hydrogen sulfide?H₂S?is a poisonous gas with a smell similar to that of rotten eggs.Low concentration of hydrogen sulfide can cause irritation damage to human eyes,respiratory system and central nervous system,and inhalation of high concentration of hydrogen sulfide can even lead to human death in a short time.However,recent studies have demonstrated that hydrogen sulfide can be produced during food production and fermentation.Accumulative consumption of foods with residual hydrogen sulfide can induce many diseases.Therefore,it is necessary to develop a highly selective and sensitive fluorescent probe to monitor the level of hydrogen sulfide in food in real time.Sulfur dioxide?SO₂?is an important gasotransmitter in living cells,which participates in many physiological processes.However,in the nucleus,sulfur dioxide can cause DNA strand breaks,leading to various diseases,such as tumors.Therefore,it is particularly important to develop a reliable fluorescent probe for the highly selective,rapid and sensitive detection of sulfur dioxide in the nucleus.Herein,we have rationally developed the first fluorescent probe for monitoring the concentrations of hydrogen sulfide?H₂S?in food in real-time,as well as a ratiometric fluorescent probe for detecting the levels of sulfur dioxide in the nucleus.Specific research contents are as follows:?1?Development of fluorescent probe for hydrogen sulfide.we initially synthesized blue fluorophore phenimazole with high fluorescence quantum yield through incorporating p-hydroxybenzaldehyde with phenanthrenequinone.By introducing 2,4-dinitrobenzene,a novel fluorescent probe for hydrogen sulfide recognition was designed and developed on the basis of photoinduced electron transfer?PET?.Before treatment with hydrogen sulfide,the probe displayed almost no fluorescence due to the PET process between fluorophore and 2,4-dinitrophenyl group.However,when the probe was reacted with hydrogen sulfide,2,4-dinitrophenyl group in the probe molecule was removed,thus the fluorescence of the fluorophore was recovered.Optical studies exhibited that the fluorescent probe showed high selectivity and sensitivity to hydrogen sulfide in aqueous solution.In addition,practical application shows that the fluorescent probe can detect the concentration of hydrogen sulfide in food samples in real time.?2?Development of fluorescent probe for sulfur dioxide.Coumarin fluorescent group was conjugated with 2-methylpyridine Chlorobenzyl salt via carbon-carbon double bond.Based on the mechanism of regulating intramolecular charge transfer?ICT?efficiency,a ratiometric fluorescent probe for sulfur dioxide with nuclear localization function was judiciously developed.Optical experiments showed that the fluorescent probe itself has an intense fluorescence in red channel.After reacting with sulfur dioxide,the fluorescence in the red channel disappeared,and the fluorescence in the blue channel emerged and increased concomitantly,resulting in a ratiometric fluorescence response.Moreover,the probe exhibited highly selective and sensitive response to sulfur dioxide.Fluorescence imaging experiments showed that the fluorescent probe can not only specifically accumulated in the nucleus,but also selectively detect the concentration of exogenous and endogenous sulfur dioxide in the nucleus.