Design,Synthesis And Application Of Novel Fluorescent Probes For Hydrogen Sulfide And Mitophagy

The discovery of green fluorescent protein(GFP)and the chemical labeling of fluorescent dyes as a multifunctional tool for live cell imaging have triggered a revolution in life science and biomedical research.With the continuous development of the fluorescent probe toolbox and imaging platform,non-invasive and informative imaging experiments are possible.In the past ten years,fluorescent probes have made significant impacts in many fields such as materials science,life sciences,and information science.Fluorescent probe technology has become ahot biomedical research tool,and it has now been widely usedThe research on cells and even living organisms has made great progress.H2S is a colorless,highly toxic acid gas with an unpleasant smell of rotten eggs.H2S can affect the eves,respiratory and central nervous system even at low exogenous concentrations.H2S along with NO and CO,is considered to be the third multifunctional signaling biomolecule because it acts as a neur om o dul at or in the humnan brain and is considered an important gas transmitter in hum an physiology.Therefore,real selective identi fi cation and detection of hydrogen sulfide in org anisms is of great significance in biochemistry.This paper designs and synthesizes a hydrogen sulfide responsive fluorescence probe LW-N3 with near-infrared excitation and emission by using a near-infrared amino semiflora derivative dye as a fluorophore and introducing azide as a group for H2S in its structure.The results of in vitro experiments show that probe LW-N3 has the ability of good water solubility:high sensitivity,high selectivity and rapid respoase to H2S in a neutral buffer solution.Cell imaging experiment results table probe LW-N3 can specifically conduct imaging analysis and detection of H2S in mitochondria.It is a highly sensitive,highly selective and well soluble mitochondrial targ eting H2S response organic fluorescent probe.Mitophagy is a process in which cells remove dysfunctional mitochondria and recycle their constituents in a lysosome-depepedent manner.To explore this process:we synthesized a novel fluorescent probe Rh-Tz based on bioorthogonal chemical reaction,which utilized the DA chemical reaction of Rh-Tz with Lvso-TCO to monitor the mitophagy process.The probe is rhodamine-based,and the positively charged ionic structure can target the mitochondria,so the probe will accumulate in the mitochondria,and the tetrazine in the probe can quench the fluorescence of the probe.The morpholine in Lyso-TCO is weakly alkaline,so it will be enriched in lysosomes.When autophagy occurs in cells by starvation,the probe in mitochondria and Lyso-TCO in lysosomes are in close contact,so the D-A reaction occurs,and the reaction is very rapid.At this time,the tetrazine structure in the probe is destroyed,and the fluorescence of the probe is recovered.We successfully achieved detection of mitophagywith high sensitivity by using the probe Rh-Tz.