Design,synthesis And Application Of Fluorescent Probes For Sulfur Dioxide And Human Serum Albumin

The fluorescent probe uses a fluorescent substance as an indicator,which causes the indicator to fluoresce at a certain excitation wavelength,and realizes the quantitative or qualitative analysis of the detected object by detecting the fluorescence.Because it has the advantages of low cost,high sensitivity,selectivity,convenient operation,and no need for pretreatment,it has a wide range of applications in biochemistry,molecular biology,medicine and other fields.Sulfur dioxide(SO₂)is very important in the environment and biology.SO₂ is often produced through the burning of fossil fuels,and it is a major pollutant and an important component of acid rain in many developing countries.SO₂ enters the human body through breathing,and it exists in the human body in the form of sulfite(SO₃^2-)and bisulfite(HSO₃^-).Abnormalities of sulfite(SO₃^2-)and bisulfite(HSO₃^-)cause many diseases,such as diarrhea,asthma,chronic bronchitis and cancer.Therefore,the development of a method for detecting SO₃^2-with high sensitivity and specificity has become an urgent problem in biological systems.In the second chapter of this paper,we designed and synthesized a novel structure and a large stokes shift fluorescent probe IPD-SFT for the detection of SO₃^2-,the probe uses imidazo[1,5-?]pyridine as the basic fluorophore,With ethyl cyanoacetate as the recognition group.The advantages of IPD-SFT include short response time,high selectivity,high sensitivity(LOD=50 n M)and wide p H adaptability(5.0-11.0).In addition,IPD-SFT can monitor exogenous and endogenous sulfites.It provides a potential tool for the monitoring of intracellular sulfite.Human serum albumin(HSA)is the most abundant transporter in human plasma and plays an important role in different physiological processes.It can transmit hormones,regulate osmotic pressure,transport nutrients,drugs and metabolites,so it plays a very important role in pharmacokinetics and efficiency.In addition,human serum albumin is considered to be an important biomarker for early warning of diseases such as kidney disease,diabetes,coronary heart disease,and neurological metabolic disorders.Therefore,accurate quantitative detection of human serum albumin has extremely important research value in the fields of biological sciences and clinical medicine.In the third chapter of this article,a fluorescent probe D-HSA based on the structure of rhodanine was designed and synthesized for the detection of HSA.After the probe specifically binds to the drug binding sites IIA and IIIA of HSA,the fluorescence is enhanced by more than 100 times,and the fluorescence intensity shows a good linear relationship within the range of HSA concentration of 0?0.5mg/m L(R²=0.91359),the detection limit is low(0.0031 mg/m L).Compared with other biological macromolecules,common amino acids,cations,and anions,probe D-HSA only shows good selectivity for HSA,and can distinguish human serum albumin from bovine serum albumin.At the same time,the probe D-HSA was used in competitive inhibition experiments to clarify the binding mechanism of the probe and HSA.In addition,the fluorescent probe D-HSA can be used for intracellular imaging.All in all,this study developed and optimized the above two new types of fluorescent probes to achieve the purpose of real-time monitoring of sulfite and human serum albumin.At the same time,it also provides new design ideas for the future development of SO₂ and HSA fluorescent probes.