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The Application Of Electrochemical Sensors Based On Porphyrin Nanocomposites

Posted on:2015-03-01Degree:MasterType:Thesis
Country:ChinaCandidate:Y J FengFull Text:PDF
GTID:2298330422983394Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
Porphyrins and their derivatives were amount of specifc biological moleculesextensively existed in nature, which play an important role in many nature of lifeactivites,for instance photosynthesis of plants, oxygen transport and catalysis in themammals, theywere called “Pigment of Life”. Porphyrins were a part ofthe hydrogenatoms on the porphine ring are substituted by other atoms/functional groups of amacrocyclic organic compound, have versatile π-conjugated planar, exhibit ultrafastelectron injection, charge-recombination kinetics siowly, absorption coefficientshighly, unique chemical and physical stability. Moreover, porphyrins are importantcarriers of redox potential in biology and chemistry. Their redox properties make themuseful in molecular electronic applications. In part because porphyrins and theirrelatives absorb light strongly in the visible, they are significant in solar energyconversion, medicine, and photonics. The ability of metalated porphyrins to bind axialligands leads to applications in sensing and molecular recognition. Some of thesefunctions require that porphyrins be oxidized or reduced and then transport charge toan electrode for collection and solar cells. In principle,the application mainlyelectrical conducting or semiconducting porphyrin polymers or fimes are particularlyinteresting. In this paper, we preparated porphyrin organic nanomaterials combinedwith some inorganic nanoparticles, these nanomaterials showed perfectly property.The results were exhibited as follows:1Preparation of-Al2O3/BATPP modified biosenseor for AA. Synthesis of5,15-bis(p-amino)-Tetra phenylporphyrin and-Al2O3nanocomposite modifiedglassy carbon electrode, at the same time establish a-Al2O3/BATPP/GCEelectrochemical sensors aim for electrochemical detection single ascorbic acid, uricacid and dopamine. The results shown as the nano-composites of-Al2O3/BATPP hasa special geometry, particularly large surface area in the surface, its was electriccatalytic oxidation spike potential for ascorbic acid, dopamine and uric acidrespectively. The surface morphology of nanocomposites were characterized byscanning electrochemical microscopy (SEM), And used the CV and DPV methods for study of different modified electrode in AA, DA and UA mixed solution response. Theresults indicated that well-defined and well-resolved voltammetric responses can bereached. This study initiate a simple and versatile protocol which could be used for aneffective way for voltammetric peak separation of AA, DA, and UA.2Preparation of porphyrin and AuNP (THPP@Au) core-shell structure. Byone-pot method prepared porphyrins and gold (THPP@Au) core-shell structure, usingthe weakly reducing the ability of tetra-hydroxyphenyl porphyrin (THPP) molecule toreduced the HAuCl4to get AuNP, meanwhile porphyrin gathered on the AuNP surfaceforming the shell structure. To optimize the the experimental conditions for thepreparation of about40-60nm nanoparticles in size, and the layer thickness ofporphyrin5-10nm approximately, the size of the gold is about40nm. While the loadthe composite structure on graphene to detcion of nitrobenzene, and achieved idealresults. The core-shell structure were characterization By SEM, TEM, EDX, XPS, andrest techniques.3The electrochemical behaviors and determination of dopamine on OMCmodified glassy carbon electrodes. The results show that the OMC/GCE electroderesolved the overlapping voltammetric responses of AA, DA and UA with latentdifference of225mV (AA to DA),123mV (DA to UA) for cyclic voltammetry (CV),respectively, which open new domain for development of the electrochemical sensorfor the simultaneous determination of DA, UA and AA in practice sample analysis inthe future.
Keywords/Search Tags:porphyrin, nanocomposites, dopamine, core-shell structure, biosensors, grapheme
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