Construction Of Electrochemi Luminescence Sensing Platform Based On Resonance Energy Transfer Signal Amplification Strategy And Its Applications

Electrochemiluminescence?ECL?is a kind of detection technology which combines electrochemistry and chemiluminescence,with the advantages of high sensitivity,wide linear range and good selectivity.The technique has been exhibited its great promising in many fields such as environmental analysis,disease diagnosis,and forensic identification.Among them,the ECL measurements for disease-related biomarkers as one of the hot topics,has attracted the attention of researchers.In order to realize sensitive and accurate detection of biomarkers,Au nanorods?Au NRs?,Silver-polyamidoamine nanocrystals?Ag-PAMAM NCs?,and rGO-Au functionalized nanocomposites were synthesize,and combining ECL detection with ratiometric method and spatial resolution technique,a series of ECL sensing platform were developed for highly sensitive and accurate detection of microRNA-21,cTnI,Myo,and CEA based on RET and enzymatic signal amplification strategies.The main innovations and research contents are as follows.1.Cathodic electrochemiluminescence behaviour of MoS₂ quantum dots and its biosensing of microRNA-21The cathodic ECL behaviour of nontoxic MoS₂ quantum dots?QDs?was studied for the first time using potassium peroxydisulfate as the co-reactant.Ag-PAMAM NCs,serving as difunctional tags for quenching and enhancing ECL of MoS₂-reduced graphene oxide composites,were introduced into the ECL detection system for signal amplification.By modulating the interparticle distance between MoS₂ QDs and Ag-PAMAM NCs,the ECL quenching from resonance energy transfer?RET?and the ECL enhancement from surface plasma resonance were realized.Coupling the good ECL performance of MoS₂ QDs with the excellent ECL quenching and enhancement effects of Ag-PAMAM NCs,a novel MoS₂ QDs-based ECL biosensing platform for sensitive detection of microRNA-21 with a range of 1×10^-15–1×10^-1010 mol/L and a detection limit of 0.20 fmol/L?S/N=3?.This method was successfully applied to the determination of microRNA-21 in human serum samples with recoveries of 90.0–110.0%and the relative standard deviations are no more than 5.8%,suggesting great potential for its applications in biological and chemical analysis.2.A spatial-resolved electrochemiluminescence ratiometric biosensor sensitive detection of cardiac troponin IA spatial-resolved ECL ratiometric assay platform was constructed based on RET and enzymatic signal amplification for sensitive detection of cardiac troponin I?cTnI?.First,CdS NWs and luminol-gold nanoparticles?L-Au NPs?were immobilized onto dual-disk glassy carbon electrode?DDCE?as cathodic and anodic luminescent nanomaterialson,respectively.After the stepwise modification of the GLD,anti-cTnI,BSA,and cTnI onto the WE1 and WE2 respectively,the WE1 were incubated with varied concentration of cTnI as working electrode and the WE2 were incubated with fixed concentration of cTnI as reference electrode.Final,the anti-cTnI-rGO-Au-CAT immobilized onto the WE1,the assay of cTnI was realized by the ratio of anodic ECL signal from working electrode to the cathodic ECL signal from the reference electrode.The signal probes prepared by loading CAT and anti-cTnI on rGO-Au were used for achieving multiple signal amplification.On the basis of the spatial-resolved ratiometric ECL sensor for sensitive detection of cTnI was achieved with a linear range of 5.0×10^-13–1.0×10^-77 g/mL at a detection limit of 0.10 pg/mL.Besides,the strategy was successfully appliedfor cTnI determination in human serum samples and the results were consistent with those of Xinyang Central Hospital.The recoveries of cTnI of the range from 90.0–110.0%and the RSD are no more than 6.7%.3.A spatial-resolved electrochemiluminescence aptasensor for carcinoembryonic antigen detection in a double-check modeA spatial-resolved ECL aptasensing platform for sensitive protein detection was constructed in a double-check mode.CdS-C composites as cathodic ECL emitters and L-Au NPs as anodic ECL emitters were immobilized on working electrode 1?WE1?and working electrode 2?WE2?of the DDCE,respectively.The platform was designed by integrating Ag-PAMAM NCs-labeled biotin-aptamer?Ag-PAMAM-bio-Apt?with the ECL emitters on the DDCE.The in-situ consumption of co-reactants in the ECL system by Ag-PAMAM NCs resulted in the great ECL quenching on both WE1 and WE2.The RET between L-Au NPs and Ag-PAMAM NCs made the ECL on WE2further decrease.In the presence of carcinoembryonic antigen?CEA?,portions of Ag-PAMAM-bio-Apt detached from the DDCE because of the competitive reaction of CEA and cDNA toward to Ag-PAMAM-bio-Apt,generating an enhancement of ECL intensity.This strategy achieves the detection of CEA in a double-check mode with detection limits of 0.39 pg/mL for the cathodic assay?WE1?and 0.20 pg/mL for the anodic assay?WE2?,respectively.Furthermore,the proposed method had been successfully applied to determine CEA in human serum sample with the recoveries of CEA of the cathodic assay?on WE1?range from 80.0%to 104.8%with the RSDs less than 5.2%,and the recoveries of CEA of the anodic assay?on WE2?are in the range of80.0%to 110.0%with the RSDs no more than 7.7%,showing great potential in cancer diagnosis.4.A novel electrochemiluminescence resonance energy transfer system for simultaneous determination of two acute myocardial infarction markers using versatile gold nanorods as energy acceptorsIn this work,a novel ECL-RET system was designed for simultaneous detection of myoglobin?Myo?and cTnI.The CdS NWs and RuSi@Ru?bpy?₃²⁺NPs were used as the ECL donors on cathode and anode,respectively,with Au NRs as the ECL acceptor.Au NRs with two absorption peaks are easily tuned to match well with the ECL emission spectra of the CdS NWs and RuSi@Ru?bpy?₃²⁺NPs.When the anti-Myo/cTnI-Au NRs is introduced into the system,the ECL signals at both CdS NWs and RuSi@Ru?bpy?₃²⁺NPs could be quenched,causing effective signals amplification for proteins detection.Moreover,this immunosensor platform also realized the simultaneous detection of two biomarkers acute myocardial infarction.On the basis of the ECL-RET immunosensor,This ECL-RET strategy could be used to detect Myo and cTnI with the linear ranges of 5.0×10^-1313 to 5.0×10^-77 g/mL and 1.0×10^-1212 to 1.0×10^-77 g/mL,with detection limits of 0.20 pg/mL for the cathodic assay and0.50 pg/mL for the anodic assay,respectively.The recoveries of Myo of the cathodic assay?on WE1?range from 89.6%to 120.0%with the RSDs less than 8.0%,and the recoveries of cTnI of the anodic assay?on WE2?are in the range of 86.0%to 116.0%with the relative standard deviations no more than 6.8%.This work provides a new road of the develpoment of RET-based ECL bioassay and disease early diagnosis.