氧化钼纳米结构可控制备及其表面等离子体共振特性研究

发布时间：2018-05-15 01:22

本文选题：氧化钼 + 纳米结构　；参考：《南京理工大学》2017年硕士论文

【摘要】：局域表面等离子体共振(LSPR)是纳米材料表面的电荷在入射光的交变电场的驱动下产生的集体共振,并为纳米材料带来近场增强效应。这种新奇的光电性能被广泛应用光电器件、生物、化学、医疗等领域。材料的表面等离子体共振特性主要由其载流子浓度决定,目前研究较为深入的表面等离子体共振材料多为贵金属和重掺杂半导体,由于载流子浓度的不同,他们的共振区间分别在可见光、红外光波段,然而由于固有缺陷和成本问题,这些材料很难在近红外区域,即生物窗口(700-1200nm)产生强烈的等离子体共振,因而限制了其表面等离子体共振特性在生物领域的应用。本论文采用液相激光烧蚀与溶剂热合成相结合的方法制备了 MoO_2纳米棒、MoO_3纳米片等多种氧化钼纳米结构,有效调控了氧化钼纳米结构的形貌、微观结构、晶体结构、成分及价态,阐明了各氧化钼纳米结构之间的转变规律,提出了乙醇以及双氧水高温分解产生的氧气与激光之间的相互作用对于氧化钼中钼离子均有还原作用,从而导致了低价态的Mo4+的产生;而亚稳的MoO_2.68纳米球随着烧蚀时间的延长逐渐堆积成氧化钼方块,且已填充的氧化钼方块逐渐生长出片层状的正交相Mo03纳米结构,当烧蚀时间进一步延长,所有堆积的氧化钼立方块都转变为了层层堆叠的纳米片,即亚稳的MoO_2.68纳米球通过堆叠组合的方式转变成了高结晶性的正交相MoO_3纳米片。通过实验观察到了合成的MoO_2纳米结构具有局域表面等离子体共振特性,并结合模拟计算证实了 MoO_2纳米结构确实在近红外区域具有非常明显的LSPR特征吸收峰,峰位在800 nm附近。同时我们首次发现MoO_2纳米结构的LSPR峰位对环境介质和其微观形貌具有明显的依赖关系,随着环境介质介电常数增加,MoO_2纳米棒的LSPR峰位产生800-1010 nm的红移;随着长宽比减小,MoO_2纳米结构的LSPR峰位也产生了红移,这些变化趋势与理论计算结果相吻合。环境介质和其微观形貌对MoO_2纳米结构LSPR特性的影响规律,对于调控MoO_2纳米结构LSPR特性及优化LSPR性能具有非常重要的意义。且MoO_2纳米结构的LSPR峰位刚好与生物窗口相匹配,实验研究结果为其在生物领域的应用提供了很好的理论基础。探究了 MoO_2纳米颗粒作为一种光热治疗癌细胞药剂的光热升温性能、生物相容性、光热杀死癌细胞的能力以及在生物体中的肿瘤抑制效果。研究结果表明MoO_2具有优异的光热升温性能,激光辐照5分钟升温可达37.5℃。同时MoO_2纳米颗粒具有优异的光热稳定性和生物相容性,其光热升温效应可以有效杀死癌细胞,且MoO_2的光热治疗可以有效抑制小鼠肿瘤的生,最高抑制率达到80.45%。这些研究有力地证明MoO_2纳米颗粒确实是一种非常优秀的光热治疗癌症的纳米药剂,MoO_2的这一出色的治疗效果,为寻找稳定、有效、廉价的光热试剂提供了新的思路,对于光热治疗的研究具有重要意义。
[Abstract]:Local surface plasmon resonance (LSPR) is the collective resonance generated by the charge of the surface of nanomaterials under the alternating electric field of the incident light, and brings the near-field enhancement effect for nanomaterials. This novel photoelectric property is widely used in the fields of optoelectronic, biological, chemical, medical and other fields. The surface plasmon resonance characteristics of the material are main. In order to determine the carrier concentration, the most deeply studied surface plasmon resonance materials are precious metals and heavily doped semiconductors. Because of the difference of the carrier concentration, their resonance ranges are in visible light and infrared wavelengths, however, due to inherent defects and cost problems, these materials are difficult to be in the near infrared region, that is, biology. The window (700-1200nm) produces a strong plasma resonance, thus limiting the application of the surface plasmon resonance in the biological field. In this paper, a variety of molybdenum oxide nanorods such as MoO_2 nanorods, MoO_3 nanoscale and other molybdenum oxide nanostructures have been prepared by the combination of liquid laser ablation and solvent thermal synthesis, which effectively regulate the molybdenum oxide nanorods. The morphology, microstructure, crystal structure, composition and valence state of the molybdenum oxide nanostructures are clarified. The interaction between oxygen and laser produced by high temperature decomposition of ethanol and hydrogen peroxide has a reduction effect on molybdenum oxide in molybdenum oxide, resulting in the production of low valence Mo4+ and metastable MoO The _2.68 nanospheres gradually accumulate into molybdenum oxide blocks with the prolongation of the ablation time, and the filled molybdenum oxide blocks gradually grow out of lamellar orthogonal phase Mo03 nanostructures. When the ablation time is further extended, all the accumulated molybdenum oxide blocks are converted to stacked nanoscale, that is, metastable MoO_2.68 nanospheres pass through the heap The method of superposition is transformed into a highly crystalline MoO_3 nanoscale. It is observed by experiments that the synthesized MoO_2 nanostructures have local surface plasmon resonance characteristics, and it is proved that the MoO_2 nanostructure has a very obvious LSPR characteristic absorption peak in the near infrared region, and the peak position is near 800 nm. At the same time, we found that the LSPR peak of the MoO_2 nanostructure has a significant dependence on the environment medium and its micromorphology. With the increase of dielectric constant, the LSPR peak of the MoO_2 nanorods produces a red shift of 800-1010 nm, and the LSPR peak of the MoO_2 nanostructure has a red shift with the decrease of the ratio of length to width. The results of theoretical calculation coincide. The influence of environmental media and its micromorphology on the LSPR properties of MoO_2 nanostructures is of great significance for the regulation of the LSPR properties of MoO_2 nanostructures and the optimization of LSPR properties. And the LSPR peak of the MoO_2 nanostructure is just matched to the biological window, and the experimental results are in the biological field. By providing a good theoretical basis, the MoO_2 nanoparticles as a kind of photothermal treatment of cancer cell agents photothermal heating performance, biocompatibility, the ability to kill cancer cells by photothermal and the effect of tumor inhibition in living organisms. The results show that MoO_2 has excellent photothermal heating performance, laser irradiation is up to 5 minutes. At the same time, the MoO_2 nanoparticles have excellent photothermal stability and biocompatibility. The photothermal heating effect can effectively kill cancer cells, and the photothermal treatment of MoO_2 can effectively inhibit the growth of tumor in mice. The highest inhibition rate reaches 80.45%.. These studies strongly prove that the MoO_2 nanoparticles are really a very excellent photothermal heat. The excellent therapeutic effect of MoO_2, a nanoscale agent for cancer treatment, provides new ideas for finding stable, effective and inexpensive light and heat reagents. It is of great significance for the study of photothermal therapy.

【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ136.12;TB383.1

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