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The Synthesis And Separation Of Carbon Dots And The Study Of Interaction Between MOFs And Enzyme

Posted on:2016-04-30Degree:MasterType:Thesis
Country:ChinaCandidate:P Y WangFull Text:PDF
GTID:2271330470969065Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
As a member of the family of carbon nanomaterials, CDs have become a new class of quantum dot-similar fluorescent nanomaterials, which have unique luminescent properties, such as excitation-dependent emission behavior and upconversion photoluminescence. These properties of CDs may be related to the size distribution, so we try to separate different sized component and explore the relationship between the size and photoluminescence properties. Metal-organic frameworks(MOFs) have attracted more attention in materials science. Thermal and mechanical stability and large pore volumes make them potential application value in the advanced selective catalysis, sensors and efficient gas storage. Large pore structure and high surface area make them ideal carrier in the application of protein immobilization. In this thesis, CDs were firstly prepared through a hydrothermal method, and then separated with a simple gel column. Moreover, the interaction between MOFs and horseradish peroxidase(HRP) was also researched. The main contents and results are included as the following:1. Synthesis and separation of CDsUsing sodium citrate and ammonium acetate as reactants, we synthesized CDs by hydrothermal treatment and further explored the reaction conditions, and finally optimized the best experimental conditions. The obtained CDs were characterized by FT-IR, Ultraviolet–visible(UV–vis) absorption spectra and fluorescent spectra. It was found that the CDs had obviously excitation-dependent emission and upconversion photoluminescence by studying their luminescent properties. Components with different sizes of carbon dots were separated using Sephadex G-10 column chromatography and obtained ideal results that excitation wavelengths, emission wavelengths and quantum yields of different components had a significant change.2. Investigation of the interaction between MOFs and HRPFirstly, we studied the adsorption of MOFs to HRP and found that HRP could be well adsorbed on MOFs with high immobilization efficiency(77.76%). By means of nitrogen adsorption/desorption and FT-IR, MOFs were characterized before and after immobilizing HRP. The results showed HRP was not only adsorbed on the surface of MOFs, but also further entered into the pores of MOFs. The mechanism of the interaction between MOFs and HRP was discussed by adsorption isotherms, and showing the results indicated that adsorption of HRP on MOFs materials was more in line with Langmuir adsorption model, which belonged to a single molecular layer of physical adsorption. Finally, using o-phenylenediamine as the chromogenic substrate, the catalytic activity of immobilized HRP for H2O2 was evaluated and we found that affinity interaction between immobilized enzyme and substrate was stronger than the free enzyme. Therefore, porous materials MOFs can be used as a good enzyme immobilization carrier in the further application.
Keywords/Search Tags:Carbon dots, Size separation, Column chromatography, MOFs, Immobilized enzyme, Horseradish peroxidase
PDF Full Text Request
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