多孔氧化铝膜与贵金属纳米颗粒复合结构的表面增强荧光效应研究
发布时间:2019-05-24 13:40
【摘要】:具有纳米结构的金属衬底,在外光场激发下,其表面所产生的表面等离激元会导致金属衬底附近的局域电磁场分布发生改变。因此,位于衬底表面附近的荧光物种的荧光辐射将受到调制,相比自由态的荧光分子而言,其荧光辐射效率大幅提升的现象称为表面增强荧光效应。在实际应用中,检测环境对光谱测量技术的灵敏度的要求不断提高,表面增强荧光效应凭借其高灵敏度的特点,受到越来越多的科研工作者青睐。且随着纳米技术的迅猛发展,人们从纳米材料的性质、衬底尺寸的调整、表面形貌的修饰等方面,对表面增强荧光效应展开研究。同时,在理论研究方面,构建了局域场增强理论、能量转移理论、辐射衰减速率理论等三大理论模型,为表面增强荧光效应的实验探究提供了理论支持。在表面增强荧光效应的研究中,衬底制备的探究成为了研究人员关注的热点之一。目前,纳米线、纳米球、纳米棒、纳米花等形貌的衬底结构,已被广泛应用到表面增强荧光效应中。利用氧化还原法、磁控溅射法、热蒸镀法等制备得到银岛膜、球形金胶、三角银胶、棒状金胶等多种形貌的纳米结构衬底,为系统研究表面增强荧光效应提供了良好的样品平台。然而,上述衬底在实现大面积、均匀性的增强衬底探索方面,具有一定的不足,从而限制其大规模推广。众所周知,多孔氧化铝膜具有六角形蜂窝状孔洞结构,孔径大小可控,孔洞分布均匀,孔道取向性良好,与膜表面垂直等特点。在表面增强拉曼散射的研究领域,利用多孔氧化铝膜制备高度有序的增强衬底,已经取得了广泛的应用。但在表面增强荧光效应研究中,基于多孔氧化铝膜的衬底制备等研究却鲜有报道。本论文利用多孔氧化铝膜作为模板,综合运用电化学沉积法、离子溅射法等多种手段,制备出多孔氧化铝膜与贵金属纳米颗粒复合结构衬底,同时对其表面增强荧光效应进行了研究,获得工艺简单、成本低廉、形貌易控、大面积均匀性好、荧光增强效果显著的金属纳米颗粒复合结构衬底。主要工作及结论如下:1、多孔氧化铝膜的制备及荧光光谱测量通过二次氧化法制备得到含有均匀分布的六角形蜂窝状孔洞网格的多孔氧化铝膜衬底。采用场发射扫描电子显微镜进行形貌表征。利用激光光谱学方法,研究扩孔处理对多孔氧化铝膜表面增强荧光效应的影响规律。结果表明,未经扩孔处理的多孔氧化铝膜具有较强的增强作用,相比于扩孔处理的增强因子最大可达3.8。分析表明,未经扩孔处理的多孔氧化铝膜具有独特的三维表面形貌,其自身表面积增大,更有利于荧光效应的增强。2、多孔氧化铝模板调制金银复合纳米结构的制备及其表面增强荧光效应的研究应用电化学沉积的方法,在多孔氧化铝膜的孔洞之中依次沉积金、银纳米颗粒,制备得到一种受AAO调制的Au/Ag复合纳米结构衬底。实验中选取Rh6G分子作为荧光探针分子,在532nm激光激发下,对该新型衬底表面增强荧光效应进行了研究。结果表明,所制备衬底具有显著的荧光增强效果,最大增强倍数约8.5倍,且随着孔密度的减小,增强因子变大。从局域场增强理论、金/银纳米颗粒的电磁响应特性等角度,对该复合衬底的表面增强荧光效应进行分析讨论。3、金银纳米颗粒修饰的多孔氧化铝膜复合结构衬底的表面增强荧光效应研究分别采用离子溅射和电化学沉积的方法,获得了经金银纳米颗粒修饰的多孔氧化铝膜复合结构衬底,研究了该衬底对Rh6G的荧光增强效应。在532nm激光激发下,获得了平均值为2.6倍的荧光增强因子。根据辐射衰减速率增加理论,对所观察到的实验现象进行了分析讨论。
[Abstract]:The metal substrate with the nano structure, under the excitation of the external light field, the surface of the metal substrate and the like away from the exciting element can cause the local electromagnetic field distribution near the metal substrate to change. Thus, the fluorescence radiation of the fluorescent species located near the surface of the substrate will be modulated, and the phenomenon of a significant increase in the fluorescence radiation efficiency of the fluorescent molecule in the free state is called a surface-enhanced fluorescence effect. In the practical application, the requirement of the detection environment to the sensitivity of the spectral measurement technology is continuously improved, and the surface-enhanced fluorescence effect is favored by an increasing number of scientific researchers by virtue of its high sensitivity. And with the rapid development of the nano technology, the surface-enhanced fluorescence effect is studied from the aspects of the properties of the nano-materials, the adjustment of the size of the substrate, the modification of the surface morphology, and the like. At the same time, in the aspect of theory research, three theoretical models, such as the local field enhancement theory, energy transfer theory and radiation attenuation rate theory, are built, and the theoretical support is provided for the experimental investigation of the surface-enhanced fluorescence effect. In the study of the surface-enhanced fluorescence effect, the research on the preparation of the substrate has become one of the hot spots of the researchers' attention. At present, the substrate structure, such as nanowires, nanospheres, nanorods, nano-flowers, and the like, has been widely used in the surface-enhanced fluorescence effect. The nano-structure substrates such as the silver island film, the spherical gold glue, the triangular silver glue and the rod-shaped gold glue are prepared by using an oxidation reduction method, a magnetron sputtering method, a thermal evaporation method and the like to provide a good sample platform for the surface-enhanced fluorescence effect of the system. However, the above-mentioned substrate has a certain disadvantage in realizing large-area and uniform enhancement of substrate exploration, thereby limiting its large-scale popularization. It is well known that the porous aluminum oxide film has the characteristics of hexagonal honeycomb-shaped hole structure, controllable pore size, uniform pore distribution, good channel orientation, and perpendicular to the surface of the film. In the field of surface-enhanced Raman scattering, a highly ordered reinforced substrate was prepared by using a porous alumina film, and a wide range of applications has been achieved. However, in the study of the surface-enhanced fluorescence effect, the preparation of the substrate based on the porous alumina film is rarely reported. in this paper, a porous alumina film is used as a template, and a porous aluminum oxide film and a noble metal nanoparticle composite structure substrate are prepared by using a plurality of means such as an electrochemical deposition method and an ion sputtering method, The metal nanoparticle composite structure substrate has the advantages of low cost, easy control of appearance, good large area uniformity and remarkable fluorescence enhancement effect. The main work and conclusion are as follows:1, the preparation of the porous alumina film and the fluorescence spectrum measurement are prepared by a secondary oxidation method to obtain a porous aluminum oxide film substrate containing a hexagonal honeycomb-shaped hole mesh which is uniformly distributed. The morphology was characterized by a field emission scanning electron microscope. The effect of hole-enlarging treatment on the surface-enhanced fluorescence effect of porous alumina film was studied by means of laser spectroscopy. The results show that the porous alumina film without the hole-enlarging treatment has a strong reinforcing effect, and the enhancement factor of the pore-expanding treatment can reach 3.8. The analysis shows that the porous alumina film without the hole-enlarging treatment has a unique three-dimensional surface morphology, the surface area of the porous aluminum oxide film is increased, and the enhancement of the fluorescence effect is more favorable. The preparation of the porous alumina template and the preparation of the gold and silver composite nano structure and the application of the electrochemical deposition method in the study of the surface enhanced fluorescence effect are sequentially deposited in the holes of the porous aluminum oxide film to prepare the Au/ Ag composite nano-structure substrate which is prepared by the AAO modulation. In the experiment, Rh6G is used as a fluorescent probe molecule, and the fluorescence effect on the surface of the novel substrate is studied under the excitation of 532 nm laser. The results show that the prepared substrate has a significant fluorescence enhancement effect, the maximum enhancement factor is about 8.5 times, and the enhancement factor becomes larger with the decrease of the pore density. The surface-enhanced fluorescence effect of the composite substrate is analyzed and discussed from the aspects of the local field enhancement theory, the electromagnetic response characteristics of the gold/ silver nanoparticles, and the like. The surface-enhanced fluorescence effect of the porous aluminum oxide film composite structure substrate modified by the gold and silver nano-particles adopts the method of ion sputtering and electrochemical deposition respectively, and the porous aluminum oxide film composite structure substrate modified by the gold and silver nano-particles is obtained, The effect of the substrate on the fluorescence enhancement of Rh6G is studied. The fluorescence enhancement factor of 2.6 times the average was obtained under the excitation of 532 nm laser. Based on the theory of radiation decay rate, the observed experimental phenomena are analyzed and discussed.
【学位授予单位】:陕西师范大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:TB383.1
本文编号:2484906
[Abstract]:The metal substrate with the nano structure, under the excitation of the external light field, the surface of the metal substrate and the like away from the exciting element can cause the local electromagnetic field distribution near the metal substrate to change. Thus, the fluorescence radiation of the fluorescent species located near the surface of the substrate will be modulated, and the phenomenon of a significant increase in the fluorescence radiation efficiency of the fluorescent molecule in the free state is called a surface-enhanced fluorescence effect. In the practical application, the requirement of the detection environment to the sensitivity of the spectral measurement technology is continuously improved, and the surface-enhanced fluorescence effect is favored by an increasing number of scientific researchers by virtue of its high sensitivity. And with the rapid development of the nano technology, the surface-enhanced fluorescence effect is studied from the aspects of the properties of the nano-materials, the adjustment of the size of the substrate, the modification of the surface morphology, and the like. At the same time, in the aspect of theory research, three theoretical models, such as the local field enhancement theory, energy transfer theory and radiation attenuation rate theory, are built, and the theoretical support is provided for the experimental investigation of the surface-enhanced fluorescence effect. In the study of the surface-enhanced fluorescence effect, the research on the preparation of the substrate has become one of the hot spots of the researchers' attention. At present, the substrate structure, such as nanowires, nanospheres, nanorods, nano-flowers, and the like, has been widely used in the surface-enhanced fluorescence effect. The nano-structure substrates such as the silver island film, the spherical gold glue, the triangular silver glue and the rod-shaped gold glue are prepared by using an oxidation reduction method, a magnetron sputtering method, a thermal evaporation method and the like to provide a good sample platform for the surface-enhanced fluorescence effect of the system. However, the above-mentioned substrate has a certain disadvantage in realizing large-area and uniform enhancement of substrate exploration, thereby limiting its large-scale popularization. It is well known that the porous aluminum oxide film has the characteristics of hexagonal honeycomb-shaped hole structure, controllable pore size, uniform pore distribution, good channel orientation, and perpendicular to the surface of the film. In the field of surface-enhanced Raman scattering, a highly ordered reinforced substrate was prepared by using a porous alumina film, and a wide range of applications has been achieved. However, in the study of the surface-enhanced fluorescence effect, the preparation of the substrate based on the porous alumina film is rarely reported. in this paper, a porous alumina film is used as a template, and a porous aluminum oxide film and a noble metal nanoparticle composite structure substrate are prepared by using a plurality of means such as an electrochemical deposition method and an ion sputtering method, The metal nanoparticle composite structure substrate has the advantages of low cost, easy control of appearance, good large area uniformity and remarkable fluorescence enhancement effect. The main work and conclusion are as follows:1, the preparation of the porous alumina film and the fluorescence spectrum measurement are prepared by a secondary oxidation method to obtain a porous aluminum oxide film substrate containing a hexagonal honeycomb-shaped hole mesh which is uniformly distributed. The morphology was characterized by a field emission scanning electron microscope. The effect of hole-enlarging treatment on the surface-enhanced fluorescence effect of porous alumina film was studied by means of laser spectroscopy. The results show that the porous alumina film without the hole-enlarging treatment has a strong reinforcing effect, and the enhancement factor of the pore-expanding treatment can reach 3.8. The analysis shows that the porous alumina film without the hole-enlarging treatment has a unique three-dimensional surface morphology, the surface area of the porous aluminum oxide film is increased, and the enhancement of the fluorescence effect is more favorable. The preparation of the porous alumina template and the preparation of the gold and silver composite nano structure and the application of the electrochemical deposition method in the study of the surface enhanced fluorescence effect are sequentially deposited in the holes of the porous aluminum oxide film to prepare the Au/ Ag composite nano-structure substrate which is prepared by the AAO modulation. In the experiment, Rh6G is used as a fluorescent probe molecule, and the fluorescence effect on the surface of the novel substrate is studied under the excitation of 532 nm laser. The results show that the prepared substrate has a significant fluorescence enhancement effect, the maximum enhancement factor is about 8.5 times, and the enhancement factor becomes larger with the decrease of the pore density. The surface-enhanced fluorescence effect of the composite substrate is analyzed and discussed from the aspects of the local field enhancement theory, the electromagnetic response characteristics of the gold/ silver nanoparticles, and the like. The surface-enhanced fluorescence effect of the porous aluminum oxide film composite structure substrate modified by the gold and silver nano-particles adopts the method of ion sputtering and electrochemical deposition respectively, and the porous aluminum oxide film composite structure substrate modified by the gold and silver nano-particles is obtained, The effect of the substrate on the fluorescence enhancement of Rh6G is studied. The fluorescence enhancement factor of 2.6 times the average was obtained under the excitation of 532 nm laser. Based on the theory of radiation decay rate, the observed experimental phenomena are analyzed and discussed.
【学位授予单位】:陕西师范大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:TB383.1
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