Application Of Electrochemiluminescence Sensing Analysis Based On Perylene Derivatives

Electrochemiluminescence?ECL?is a photoluminescence reaction that occurs on the surface of the electrode and is induced by electrochemistry.It combines two processes of electrochemistry and chemiluminescence.In recent years,ECL has been widely used in the field of bioassay analysis and clinical diagnosis because of its high sensitivity,high selectivity,low background signal and fast response.With the development of science and technology,a variety of cancers are coming,early detection and early treatment is very important,especially for tumor markers in very low concentrations.Therefore,it is necessarytofindsensitivedetectionmethods,andelectrochemiluminescence immunosensors,which have the advantages of electrochemical luminescence and specific recognition of immune reaction,have attracted more and more attention in the detection of tumor markers.Pyridine ruthenium and its derivatives,carbon quantum dots and other quantum dots and lumino and its derivatives are commonly used in electroluminescent sensors in recent years,and many nanomaterials with unique properties are often used to bind to these luminescent materials.Composite materials,such as graphene,titanium dioxide,platinum nanoparticles,mesoporous silica,carbon nanotubes and so on,are often used to mark second antibodies in electrochemiluminescence immunosensors for detection of tumor markers.In this thesis,ECL sensors were constructed by using organic molecules,perylene tetracarboxylic acid?PTCA?and perylene tetracarboxylic dianhydride?PTCDA?as luminescent agents.The main content consists of the following three parts:1.Preparation of ECL sandwich immunosensor based on double photoluminescence synergistic effect and its application in sensitive detection of CEABased on double photoluminescence synergistic promotion mechanism of PTCA and CQDs,a novel ECL sandwich immunosensor was constructed for the sensitive detection of carcinoembryonic antigen?CEA?.Au film was electrodeposited on the bare electrode as a platformtoimmobilizeAb₁,andthepreparednanocomposite graphene-PTCA-Cu²⁺-CQDs/AuNPs was used to label Ab₂,at the same time to amplify the detection signal.Through the specific recognition of CEA with Ab₁ and Ab₂,PTCA and CQDs can be fixed to the surface of the electrode to produce synergistic promotion of ECL signals.The method combines the strong adsorption of Au film on Ab₁,the good electronic conductivity of AuNPs on Ab₂,the large specific surface area and easy functionalization of graphene and the synergistic luminescence effect of PTCA and CQDs,and the high sensitivity detection of CEA is realized.The ECL intensity of the ECL sandwich immunosensor is linearly correlated with the logarithm of CEA concentration from 0.001fg mL^-11 to 1 ng mL^-1,The regression equation is?ECL=6428.3+935.7 lg C_CEA/pg m L^-1,correlation coefficent is 0.9986 and the limit of detection for CEA is 0.00026 fg mL^-1?3??,?was the standard deviation of the 11 parallel measurements of blank solution.The sensor has good selectivity for the detection of actual samples,at the same time,the sensor also has high sensitivity,good stability and reproducibility.This experiment also provides a new idea for the establishment of a double luminescent synergistic luminescent immunosensor,and the detection limit is greatly reduced and the sensitivity is improved.2.High performance label-free ECL sensor for sensitive detection of CEA based on PTCDABased on the principle that the effective covering of the protein on the luminescent PTCDA hinders the effective collision between the luminescent body and the solution co-reaction agent,and then causes the sensitive change of the electroluminescent intensity,a label-free electrochemiluminescence sensor is established.ECL supramolecular nanorod PTCDA-An was successfully prepared,and Au film was electrodeposited on it,then Ab₁was adsorbed on the Au film through Au-NH₂,BSA is then used to block other active sites.Finally,CEA is combined with Ab₁ through the specificity between antibody and antigen.And CEA covers some of the PTCDA molecules,with different amounts of CEA fixed,the ECL intensity of detection signal is different,the detection range is from 1 pg mL^-1to 10ug m L^-1,the limit of detection for CEA is 0.23 pg mL^-1?3??,?was the standard deviation of the 11 parallel measurements of blank solution.The label-free ECL sensor in this experiment avoids the tedious step of marking two resistance,saves time and funds,and reduces the detection limit.At the same time,the sensor has good stability,reproducibility and specificity,and satisfactory results are obtained for the detection of the actual samples.3.Preparation of non-enzyme ECL sensor based on small molecules modified DNA and PTCDA functionalized graphene and its application for the detection of FRBased on the principle that the effective covering of the protein on the luminescent PTCDA hinders the effective collision between the luminescent body and the solution co-reaction agent,and then causes the sensitive change of the electroluminescent intensity,non-enzyme electrochemiluminescence sensor for the detection of FR is established.The ECL supramolecular nanorod?PTCDA-An?was successfully prepared and grafted onto the graphene chip,FA labeled ssDNA?FA-ss DNA?was noncovalently immobilized to the graphene-PTCDA-An ECL nanomaterials and bound to folate receptors as a bridge,because there's a lot of affinity between FA and FR,and FR covers some of the PTCDA molecules,with different amounts of FR fixed,the ECL intensity of detection signal is different,the detection range is from1 fg mL^-1to 1 ng mL^-1,the limit of detection for FR is0.636 fg mL^-1?3??,?was the standard deviation of the 11 parallel measurements of blank solution.At the same time,the sensor has good stability,reproducibility and specificity,and can be successfully applied to the detection of practical samples.In addition,this scheme also provides a good method for the detection of protein without using any enzyme.