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The Construction And Optical Properties Study Of CdTe Quantum Qots @ Biomacromolecule/LDH Biological Nanocomposites

Posted on:2018-01-28Degree:MasterType:Thesis
Country:ChinaCandidate:L LiFull Text:PDF
GTID:2321330518993693Subject:Chemical Engineering and Technology
Abstract/Summary:PDF Full Text Request
Quantum dots(QDs)luminescent films are widely used in optoelectronic devices,the combination of biomolecules and quantum dots is also a hot topic.In this article,we use the two biological molecules silk fibroin(SF)and glycosaminoglycans(GAG),using LDH layerd structure,through layer by layer assembly method,effectively realizing the combination of biological molecules and quantum dots,meanwhile,achieving the immobilization of fluorescent molecules.Realizing effective dispersion of quantum dots by the hydrogen bond interaction between SF and CdTe QDs,The fluorescence intensity of CdTe QDs is enhanced,and the fluorescence quenching caused by molecular aggregation and surface defects is reduced.The main works are as follows:1.(CdTe QDs/LDH)n and(CdTe QDs@SF/LDH)n ultrathin films(UTFs)were prepared by layer by layer assembly technique.Because of the existence of SF,the fluorescence intensity and lifetime of CdTe QDs have been greatly enhanced.In the(CdTe QDs@SF/LDH)n UTFs,the beta-sheet SF has stronger fluorescence enhancement effect on the CdTe QDs than the random coiled SF.In the solution state,SF also has fluorescence enhancement effect on the CdTe QDs.2.Comparing the fluorescence stability of(CdTe QD@SF/LDH)30 and(CdTe QD@SF/PDDA)30 UTFs prepared by layer by layer assembly method with poly electrolyte PDDA and LDH co-assembled with CdTe QDs/SF mixture.LDH plays an important role in the stability of the UTFs.The fluorescence intensity of CdTe QDs/SF mixed solution increased only by 35%compared with that of the CdTe QDs aqueous solution.Compared with the(CdTe QDs/LDH)n UTFs,the fluorescence enhancement degree of random coil and beta-sheet silk fibroin are relatively 7 times and 17 times in the(CdTe QD@SF/LDH)n UTFs,which are the advantages of UTFs,showing that LDH enhanced the fluorescence enhancement effect of SF on CdTe QDs.3.(CdTe QDs@SF/LDH)n UTFs have a fluorescent response to immune disease signal protein immunoglobulin lgG,can be used for the detection of lgG concentration.In the range of lgG concentration of mg/mL in human,the fluorescence intensity of the UTFs showed a good linear relationship with the concentration of lgG,therefore,they are of great significance for the detection of many diseases.4.Three kinds of glycosaminoglycans(GAG):Hyaluronic acid(HA),chondroitin sulfate(CS),and CdTe(DS)were used to construct(Cd QDs@GAG/LDH)n UTFs.The composite films can be assembled in a sequence of layers,and because of the presence of GAG,CdTe QDs have a certain fluorescence response to water vapor and different concentrations of inorganic ions K~+ and Na~+.
Keywords/Search Tags:CdTe QDs, silkfibroin(SF), LDH, glycosaminoglycans(GAG), composite film, fluorescence enhancement
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