Coumarin-based Reactive Fluorescent Probes For The Detection Of Biological Thiols

Biothiols play a very important role in human health,and it is important to diagnose potential diseases based on their distribution and fluctuation levels.Mercury ions are very toxic,but they are widely used in life and industry.Whether it is biological mercaptans or mercury ions,traditional detection methods require various valuable instruments.Therefore,it is a huge challenge to develop simple,fast and efficient detection methods.Fluorescent probes are a good way to solve the problem!Coumarin is widely favored by scientific researchers due to its high fluorescence efficiency,large Stocks displacement,good photostability and low toxicity.According to different detection mechanisms and recognition sites,7 series of coumarin-type fluorescent probes were designed and synthesized in this paper,containing 27 compounds,25 of which are new.Four series A,B,C,and D are probes for biothiol,while series E,F,and G are fluorescent probes for metal ion.For biothiols,A1 and C1 were tested;for metal ions,F2 was tested.The contents of the dissertation mainly include the following:The A series is a Michael addition-and-detachment detection mechanism,and the propylene ester group connected to the coumarin parent is the reaction site,and the Cys test is done with A1as a representative.The results show that A1 can be used for the fluorescence detection of Cys in Et OH/H₂O(9:1,v/v)medium.After A1 was added to Cys,two broad emission bands appeared at396 nm and 458 nm respectively.After Cys was added,the fluorescence intensity at 396 nm and458 nm was increased by 4.6 and 25.1 times compared with A1.The response time of probe A1 and Cys is about 30 min,and the detection limit is 52.4 n M.In addition,probe A1 was successfully used in Hela cell bioimaging.C1 is designed and synthesized based on the mechanism of Michael addition,and the maleimide connected to the coumarin parent is the reaction site.A series of performance tests have been done on Cys.The results show that D1 can be used for the fluorescence detection of Cys in DMF and DMF/H₂O(9:1,v/v)media.After Cys was added to the C1 solution in DMF,the fluorescence intensity increased by 320 times,the response time was 5 min,and the detection limit was 4.7 n M.The sensor C1 responds to fast Cys.After Cys is added,the fluorescence intensity immediately increases by 170 times.In DMF/H₂O(9:1,v/v),the detection limit of sensor C1 for Cys is 4.7 n M,the response time is 7 min,and the detection limit is 14 n M.C1 was used to quantitatively determine the Cys content in the drug,and to perform biological imaging of Hela cells.F series are Hg²⁺fluorescent probes with thioacetal as the recognition site.F2 is selected as the representative for the fluorescence detection of Hg²⁺in Et OH/H₂O(1:1,v/v)medium.After adding Hg²⁺,the emission bands at 518 nm and 413 nm changed significantly.After adding Hg²⁺,the fluorescence intensity at 518 nm is reduced to 0.19 times compared with F2;the fluorescence intensity at 413 nm is increased by 3.1 times,the response time of probe F2 and Hg²⁺is about 70min,and the detection limit is 0.75?M.In addition,probe F2 has been successfully used on the Hg²⁺strip test paper.In terms of biological thiols,the B series molecules are also designed and synthesized based on the Michael addition mechanism,and the D series are near-infrared molecules;in terms of metal ions,the E series molecules are designed and synthesized based on the heteroatom coordination mechanism on hydrazone and imine.The G series of molecules are dual-site Hg²⁺fluorescent probes designed and synthesized based on the sulfur removal mechanism.B,D,E,and G series molecules have not undergone detailed performance testing...