【作者】 王涛；

【导师】 隋凝；

【作者基本信息】 青岛科技大学 ， 材料科学与工程， 2021， 硕士

【摘要】 过氧化物酶是维持生命体正常生理活动的重要物质,但大多数酶为蛋白质,具有价格昂贵;在高温、强酸和强碱中结构不稳定易失活;难以制备提取等缺点。通过对酶结构和催化机理的认识,合成价格便宜且具有酶催化活性中心的模拟酶来替代天然酶的使用具有重要意义。本文以新型二维碳材料石墨炔（GDY）为基础,利用简便方法制备了三种负载型过氧化物模拟酶——石墨炔负载Pd Fe合金纳米片（Pd Fe/GDY）、石墨炔负载血红素（Hemin-GDY）纳米复合材料以及金银纳米笼负载掺氮石墨炔量子点（N-GDQDs/Au Ag NCs）纳米酶,并探究了它们应用于构建生物传感器、抗菌和有机污染物降解的性能。主要研究内容如下:1.水热法制备了Pd Fe/GDY纳米片,以3,3’,5,5’-四甲基联苯胺（TMB）-H₂O₂为实验模型评估得到Pd Fe/GDY具有优异的过氧化物酶活性。根据米氏方程（Michaelis-Menten equation）、电子自旋共振（EPR）和密度泛函理论（DFT）探究了Pd Fe/GDY酶催化机理。从热力学角度解释了Pd Fe与Pd Fe/GDY酶活性差异的原因。基于Pd Fe/GDY构建了可应用于实际生物样品中谷胱甘肽（GSH）检测的可视化传感器。探究了Pd Fe/GDY作为抗菌试剂应用于伤口愈合的可行性及作用机理。2.超声法制备了Hemin-GDY和Hemin-石墨烯（GR）两种过氧化物模拟酶,采用TMB-H₂O₂为模型探究比较了两种模拟酶的催化活性。提出了负载型血红素类复合材料进行酶催化的反应循环路径。从热力学、动力学和能级结构角度探究了同属二维碳材料载体对Hemin本征催化活性影响不同的原因。基于两种复合材料的酶催化活性实现了对多巴胺的检测并探究了两种传感器的性能差异。以降解亚甲基蓝（MB）为模型探究了两种模拟酶用于降解有机污染物的性能。3.化学还原法和牺牲模板法联用制备了N-GDQDs/Au Ag纳米笼（NCs）,以TMB-H₂O₂为模型,有无808 nm近红外光照射为变量评估N-GDQDs/Au Ag NCs光增强酶催化活性的性能,探究了光增强催化活性的机理。建立了体外杀菌模型,探究了N-GDQDs/Au Ag NCs作为抗菌试剂抑制细菌生长的可行性及作用机理。更多还原

【Abstract】 Peroxidase is a kind of important substance that maintains normal physiological activities of living organisms.However,most natural enzymes are proteins with high price.Under conditions of high temperature,strong acid or strong alkali,their structure is unstable and easy to be inactivated.It is difficult to prepare and extract.Based on the understanding of the structure and catalytic mechanism of natural enzymes,it is of great significance to synthesize mimic enzymes with low price and active center to replace the use of natural enzymes.Based on graphdiyne,a promising two-dimensional carbon material,this paper mainly studied three different supported peroxidase-like nanozymes which were synthesized by facile methods:graphdiyne-supported pallium-iron nanosheets（Pd Fe/GDY）,graphdiyne-supported hemin nanocomposite（Hemin-GDY）and nitrogen doped graphdiyne quantum dots decorated Au Ag nanocages（N-GDQDs/Au Ag NCs）nanozymes,and then explored their catalytic properties through some different applications such as biosensor,antibacterial and degradation of organic pollutants.The main contents are as follows:1.Pd Fe/GDY nanosheet was prepared by a facile hydrothermal process,and the peroxidase-like activity of Pd Fe/GDY was evaluated by TMB-H₂O₂ as the model.The catalytic mechanism of Pd Fe/GDY nanozyme was studied by Michaelis-Menten equation,electron paramagnetic resonance（EPR）and density functional theory（DFT）.The difference of catalytic activity between Pd Fe and Pd Fe/GDY was explained from thermodynamics point of view.Based on the peroxidase-like activity of Pd Fe/GDY,a visual sensor for glutathione（GSH）in biological samples was constructed.The feasibility and mechanism of Pd Fe/GDY as an antibacterial agent in wound healing were further explored.2.Hemin-GDY and Hemin-GR nanocomposits were prepared by ultrasonic method,and the catalytic activity of the two nanozymes were investigated by using TMB-H₂O₂ as the model.The enzyme-catalyzed reaction cycle path was proposed,and the reasons for the different peroxidase-like activity of the two materials were investigated from the perspectives of thermodynamics,kinetics and energy level structure.Based on the peroxidase-like activity of the two nanocomposites,two kinds of sensors for detecting dopamine were constructed and the performance differences of the two sensors were explored.The application performance of two nanozymes in the degradation of organic pollutants were also investigated by using methylene blue（MB）as a model.3.N-GDQDs/Au Ag nanocages（NCs）were synthesized through chemical reduction method and sacrificial templates method.Using TMB-H₂O₂ as the model and with or without 808 nm near-infrared irradiation as the variable,the performance of photo-enhanced peroxidase-like activity of N-GDQDs/Au Ag NCs was evaluated.The mechanism of photo-enhanced catalytic activity was explored.An in vitro bactericidal model was established to explore the feasibility and mechanism of N-GDQDs/Au Ag NCs as an antibacterial agent to inhibit bacterial growth.更多还原