Detection Of Mercury Ion And Biological Thiolwith Coumarin-containing NIR Fluorescence Probe

Research and development were based on near-infrared functional fluorescent probes,which were used to analyze biologically active substances and help to study cell physiology and pathology.Many near-infrared(NIR)dyes have been developed for the analysis of biological thiols or metal ions,because NIR(650-900 nm)has lower fluorescence background interference,smaller autofluorescence,good permeability and longer Emission wavelength and other advantages.As a widely used near-infrared dye,coumarin was usually used in the design of near-infrared fluorescent probes.In the past ten years,many coumarin-based NIR fluorescent probes have been developed.However,the designed and synthesized fluorescent probe was difficult to detect Hg²⁺/Ag⁺at the same time and has poor solubility.Therefore,it is a huge challenge to design and synthesize a fluorescent probe that simultaneously detects Hg²⁺/Ag⁺and has good solubility.Based on the advantages of near-infrared and coumarin fluorophores,this topic combines them to design and synthesize fluorescent probes with good permeability for biological fluorescence imaging.According to different coumarin derivatives,4-methyl-7-hydroxy-8-formyl aroma(AL),4-trifluoromethyl-7-hydroxy-8-formyl coumarin(CCL)were designed and synthesized.and 7-diethylamino-3-formylcoumarin(KL)three series of coumarin fluorescent probe compounds,a total of 20 compounds were designed and synthesized,of which 12 were new compounds,AL2,AL3,AL4,KL1,KL2 and KL4 have detection sites for biological thiols;AL1,AL5,CL and KL3 have detection sites for mercury and silver ions.This subject chose AL1,CL,KL3 and AL3 for optical performance testing.The main content of the optical performance test of AL1 was as follows:In the Et OH/H₂O(1:1,v:v)detection system,the detection of Hg²⁺/Ag⁺by AL1 was a fluorescence-on type.Compared with the probe AL1 at 705 nm after adding Hg²⁺/Ag⁺,the fluorescence intensity increases by 12 times and 5.5 times,respectively,but there was no obvious change when other common metal ions are added;for the test of Hg²⁺anti-interference performance,add other common After the metal ions,the fluorescence intensity of AL1 was reduced by about 1 times.Similarly,for the anti-interference performance of Ag⁺,except that the fluorescence intensity was slightly reduced when Mn²⁺was added,the addition of other metal ions reduces the fluorescence intensity by about 1 times,and its anti-interference The performance was average;through the measurement of Hg²⁺/Ag⁺different concentration curves,the detection limits of AL1 for Hg²⁺and Ag⁺were calculated to be 2.7?M and 3.2?M,respectively;the response time of probe AL1 and Hg²⁺/Ag⁺were 45 s and 90 min,respectively;The stability of needle AL1 under different p H conditions shows that the probe AL1 can stably detect Hg²⁺/Ag⁺at p H=1-10.The same optical performance test was done on CL.In the Et OH/H₂O(1:1,v:v)system,the probe CL was a fluorescence-on detection for Hg²⁺/Ag⁺.After adding Hg²⁺/Ag⁺to CL,the fluorescence intensity at 695 nm increased by 15 times and 8 times compared with probe CL;after adding common metal ions,only the color of Hg²⁺and Ag⁺turns yellow,and under ultraviolet light(?=365 nm),the fluorescence color changes from blue to deep red and orange respectively,so it can be recognized with the naked eye Hg²⁺and Ag⁺;its anti-interference performance test against Hg²⁺,after adding 5 equivalents of other interfering ions,only When Ni²⁺,Ca²⁺and Fe³⁺metal ions were added,the fluorescence intensity decreases significantly,while the fluorescence intensity of other metal ions does not change significantly,while the anti-interference performance of Ag⁺is relatively poor;the detection limits of Hg²⁺/Ag⁺are calculated to be 0.88?M and 8.8?M,respectively;The response time was 120 s and 24 min,respectively,and the response time was relatively fast;the stable state of the probe CL at different p H values was explored,CL can detect Hg²⁺within p H=2–12;p H=1–6 can detect Ag⁺.Probe CL can be used for U87MG cell imaging applications.KL3 was a probe with reduced fluorescence intensity.First,it was screened for solvent effect,and finally it has the best detection effect in pure Et OH system.Compared with probe KL3 at 600 nm after adding Hg²⁺/Ag⁺,the fluorescence intensity was reduced by 2.8 times and 1.7 times,and the absorption peak blue shifted by 40 nm.After adding Hg²⁺/Ag⁺,the color of probe KL3 changed from dark yellow to dark yellow.It was colorless or light yellow,so Hg²⁺/Ag⁺can be identified with the naked eye,and the fluorescent color changes from orange to green under ultraviolet light(?=365 nm);the results of the anti-interference performance of probe KL3 show that 1 equivalents of common competition are added For Hg²⁺,only Al³⁺,Cr³⁺and Fe³⁺were added to slightly reduce the fluorescence,while other metal ions have no obvious changes.For Ag⁺,the addition of common metal ions can slightly increase the fluorescence intensity.In other words,the anti-interference performance was excellent;the detection limits of probe KL3 for Hg²⁺/Ag⁺were calculated to be 3.66?M and 5.76?M,respectively,and the response time was 45s and 120 s,respectively.Probe AL3 for the detection of Cys,Hcy and GSH three biological thiols,set excitation wavelength to?_ex=384 nm,slit width 5 nm,emission wavelength?_em=556nm,probe AL3 concentration to 20?M,add 1 After the Cys,Hcy and GSH times were increased,the results show that the fluorescence intensity of the emission peak at 556 nm is reduced by 1.6times,the fluorescence intensity has no obvious change,and the fluorescence intensity was increased by 1.33 times.Probe AL3 can detect Cys and GSH two kinds of biological thiols.