Synthesis And Biosensing Research On Biomimetic Materials Of Porphyrin And ?-Cyclodextrin

Electrochemiluminescence(ECL)is a chemiluminescence controlled by electrochemical reaction.Therefore,intrinsic electrical excitation gives the ECL high sensitivity and space-time modulability while having the advantages of broad linear range and simple operation.Using these advantages,people have developed ultra-sensitive,wide applicability and easy to operate analysis and detection methods.This has prompted the commercialization of electrochemiluminescence technology to rapidly develop and take shape in the fields of environmental monitoring,food safety and biomedical analysis.The core of electrochemiluminescence technology is luminescent materials,of which porphyrin is a class of organic electroluminescent material with excellent photoelectric conversion properties,has been widely used in the electro/photochemical and energy chemical fields.Whether biological macromolecules such as nucleic acids,proteins,or a variety of nanomaterials,and porphyrin can be assembled through a variety of ways to produce a specific performance comparable to the natural structure of bionic complexes.In this dissertation,the synthesis of porphyrin luminophore was taken as the starting point,and the sensitization of its luminescence by nanometer assembly was achieved,which was used for the ECL detection of molecules and ions.The main contents of the dissertation are as follows:(1)Preparation of bionic host-guest envelope structure and enhancement of electrophorometric chemiluminescence of zinc porphyrin for H2O2 content analysisThis part of the work is based on the deproteinization of the natural enzyme structure of porphyrin prosthetic auxiliary with the structure-activity relationship of the protein subunit-porphyrin prosthetic.The active core is extracted and the bionic topological structure is reconstructed.The "clamp" electro-optic active porphyrin Supramolecular unit.Through the synthesis of ?-cyclodextrin dimer(PyOCD-OH),mimicking the polypeptide shell of natural enzyme,the preparation of the nano-assembly is simple,the reaction is mild and the yield is high.Meanwhile,3,5-dichloromethyl Pyridine as the opening and closing of the double-lobe "pivot" and the back-supporting fulcrum,on the one hand,the tight connection symmetrical structural cavity,on the other hand with axial coordination support stable zinc ions,forming a similar histidine back Supporting the porphyrin enzyme endogenous environment(referred to as ZnTSPP@PyOCD-OH),to achieve a precise and stable auxiliary prosthetic,to avoid dimerization or polymerization of porphyrin molecular monomer situation,thus effectively solve the porphyrin The structure is characterized by the fact that the electrochemiluminescence intensity of the aqueous phase is unstable and easily quenched by the electrophilic species,thereby exhibiting high and unique ECL radiation.The special structure is clearly characterized by absorption spectrum and nuclear magnetic resonance spectrum.The axial coordination of heterocyclic nitrogen greatly improves the molecular electronic properties of the porphyrin conjugate structure.The specific performance is obtained in terms of electro-optical conversion efficiency and conversion stability Significantly increased,up to 60%.It was further found that the common enzyme-catalyzed substrate,hydrogen peroxide,significantly enhanced the ECL of the host-guest envelope structure.The electron conduction of ZnTSPP@PyOCD-OH and H2O2 was achieved through the relevant ECL experimental platform,revealing the proportional law between the resulting sensitization signal and the content of co-reactant.Using this as a detection principle,a simple peroxide sensing strategy was developed.The detection results of the standard showed a high linear correlation(R2=0.998)and a wide dynamic range(10-11?10-3M)High sensitivity(6.3 × 10-12M)?detection limit reached picomolar level.The overall reflection of the bionics as the guiding principle,to learn from the biochemical molecules or reaction materials,to rationally design the porphyrin composite structure is an effective way to improve the intrinsic properties of porphyrin and broaden its scope of application of a viable approach.(2)Exploration of electroactive center of porphyrin-based supramolecular envelopment and determination of viability of biomimetic structureThis part of the research focuses on confirming the electrophoric center of the porphyrin biomimetic envelope and measuring the activity of the luminescent structure.First,the porphyrin mimetic was reconstituted with the metal-free prosthetic 5,10,15,20-tetra(4-sulfonatopheyl)porphine(TSPP)into the lumen of PyOCD-OH.The system was found to have ECL signals if and only if Zn2+ coexisted.This shows that free zinc ions are specifically captured and intimately chelated by cyclic TSPP and pyridine nitrogen,thus forming a supramolecular electroactive center designed for the double bond.Achieved the absence of Zn2+ in the presence of ECL off/on phenomenon.This apparent signal gain mode is further used as a working mechanism for zinc-ion selective electrodes and as such serves as an indicator of viability testing in aqueous solutions.In addition,ECL "ion-selective" biochemical analysis method of ECL with high specificity,high sensitivity and wide linear range has been developed by using the strong cathodic ECL property unique to Zn porphyrin compared with other metalloporphyrins.A non-immunological model in situ easy to monitor zinc-containing protein,conjugated nucleic acid identification means to enhance the porphyrin-based ECL technology in the field of biomedical engineering sensing applications.