Construction And Application Research Of Hydrogen Sulfide Fluorescent Probe

Hydrogen sulfide（H₂S）has been regarded as the third important gaseous signal molecule in living organisms along with nitric oxide（NO）and carbon monoxide（CO）.It has been found to be involved in many physiological processes,such as immune response,angiogenesis,antioxidation,neurotransmission and apoptosis.However,abnormal expression of H₂S have also been related to many pathological processes,such as Alzheimer’s disease,Parkinson’s,Down’s syndrome,diabetes,liver cirrhosis and even cancer.Consequently,selective detection of the endogenous hydrogen sulfide is of great importance.Many methods that have been used to determine hydrogen sulfide,include gas chromatography,colorimetry,electrochemical analysis and fluorescence spectroscopy.Thereinto,fluorescence analysis has exhibited new advantages for real-time detection due to its high selectivity,sensitivity and simplicity.In recent years,many nano-fluorescence probes have been developed,especiallynovel porous nano-metal organic frameworks（NMOFs）materials,which have been exploited as fluorescence probes due to its simple synthesis methods and easier to modify.In addition,upconverting nanoparticles（UCNPs）with Near Infrared（NIR）photoexcitation have been widely used for biological detection and imaging.Based on the above background,we designed and synthesized two hydrogen sulfide fluorescence probes.The main content includes the following two parts:（1）Synthesis and properties of CuO modified nano-metal organic frameworks materialsIn this part,we synthesized a novel CuO-modified NMOF fluorescence probe based on energy-resonance transfer（FRET）using a dye-doped metal-organic framework as the donor of energy and CuO nanoparticles as the energy acceptor.When hydrogen sulfideappear,fluorescence recovery is achieved.The probe has the advantages of simple synthesis method,fast response and high selectivity.（2）Synthesis and properties of CuO modified upconversion nanoprobesIn this section,we used nanoparticles as energy donor and CuO nanoparticles as energy receptor to synthesize a novel nano fluorescence probe based on energy resonance transfer（FRET）.Firstly,we prepared two kinds of hexagonal phase upconversion nanoparticles using a high-temperature thermal decomposition method,and then through the phase transfer method successfully obtained two well-dispersed aqueous phase upconversion nanoparticles NaYF₄:Yb³⁺（20%）,Er³⁺（2%）and NaYF₄:Yb³⁺（30%）,Tm³⁺（0.5%）.Then this CuO@UCNP nano probe was synthesized by solvothermal method.Under the physiological pH conditions,hydrogen sulfide reacts with the CuO nanoparticle and the fluorescence intensity of the probe increases,which can be used as a new nano-fluorescence probe with near-infrared excitation（980 nm）for the detection of hydrogen sulfide molecules.