本文選題：DNA折紙 + 自組裝��； 參考：《南京郵電大學(xué)》2017年碩士論文

【摘要】：由于金屬納米顆粒具有獨(dú)特的光學(xué)性能,金屬納米顆粒的組裝吸引了人們的廣泛關(guān)注。不同化學(xué)成分,不同形狀,不同尺寸的金屬納米結(jié)構(gòu)被精確的組裝形成具有等離子體共振效應(yīng)(plasmonic resonance)的納米結(jié)構(gòu)。這些納米結(jié)構(gòu)表現(xiàn)出獨(dú)特的圓二色性(CD),表面增強(qiáng)拉曼(SERS)以及紫外(UV-VIS)等光譜特征。這些具有等離子體共振效應(yīng)的納米結(jié)構(gòu)能夠被廣泛的應(yīng)用在能量收集和生物傳感等方面。金屬納米結(jié)構(gòu)組裝體在以往的研究中,一般采用自上而下的刻蝕方法制備。然而該方法成本較高,而且難于制備諸如三維組裝體等較為復(fù)雜的結(jié)構(gòu)。以DNA為基礎(chǔ)的自組裝技術(shù)提供了一種自下而上的快速組裝方法來(lái)構(gòu)建高度協(xié)調(diào)的納米結(jié)構(gòu)。由于DNA納米結(jié)構(gòu)具有可尋址能力和納米級(jí)分辨率等優(yōu)勢(shì),可作為良好的模板用于組裝金屬納米粒子。本文主要設(shè)計(jì)合成了獨(dú)特的DNA納米結(jié)構(gòu)模板,利用簡(jiǎn)便、高效的方法將不同尺寸的納米金球組裝到模板的特定位點(diǎn)上,形成多種構(gòu)型的金屬納米結(jié)構(gòu)。通過(guò)對(duì)組裝的金屬納米結(jié)構(gòu)進(jìn)行SERS研究,發(fā)現(xiàn)這些金屬納米組裝體可以有效的增強(qiáng)拉曼分子的響應(yīng)信號(hào)�；谏鲜鰞�(nèi)容,本論文的研究?jī)?nèi)容分為以下三個(gè)方面:1.如何降低DNA修飾的納米金球與DNA折紙模板之間存在的電荷斥力是提高大尺寸納米金球在DNA折紙模板上定位組裝效率的關(guān)鍵。我們利用孔洞型DNA折紙作為模板組裝30 nm金球,形成二聚體和四聚體的結(jié)構(gòu)。其透射電子顯微鏡(TEM)結(jié)果表明,相比于正常DNA折紙模板,納米金球在孔洞型DNA折紙模板上的組裝效率大大提高。因金納米組裝體具有較強(qiáng)的表面等離子體效應(yīng),當(dāng)拉曼活性分子共價(jià)吸附至其表面時(shí),拉曼信號(hào)大幅度增強(qiáng)。2.DNA折紙納米結(jié)構(gòu)將一條長(zhǎng)單鏈DNA和數(shù)百條短鏈混合,經(jīng)過(guò)數(shù)小時(shí)的退火組裝進(jìn)而形成預(yù)設(shè)結(jié)構(gòu)。我們?cè)O(shè)計(jì)了一種新型DNA納米帶結(jié)構(gòu),僅需要四條DNA鏈在常溫下等比例混合二十分鐘即可形成高產(chǎn)率的微米級(jí)DNA納米帶。該納米帶還可以作為模板一步法組裝納米金球,形成長(zhǎng)的納米金鏈。通過(guò)一步法組裝不同尺寸納米金球(直徑10 nm,20 nm,30 nm)形成納米金鏈,其高密度的金球線性排列產(chǎn)生眾多的熱點(diǎn)。這些具有plasmonic性質(zhì)的納米金鏈可用于增強(qiáng)拉曼分子的SERS信號(hào)。3.利用DNA納米技術(shù),設(shè)計(jì)了一種僅僅用5條DNA鏈進(jìn)行自組裝形成微米級(jí)的二維DNA納米結(jié)構(gòu),并且用云母作為表面輔助組裝成的二維DNA納米結(jié)構(gòu)平整有序。在二維DNA納米結(jié)構(gòu)中特定位點(diǎn)伸出捕獲DNA鏈來(lái)組裝納米金球,形成高密度的二維金球陣列。這種方法能夠廣泛的應(yīng)用在制造納米尺寸的集成電路,并且形成的二維金屬納米結(jié)構(gòu)在作為優(yōu)良的SERS研究基底方面具有很大的潛力。
[Abstract]:Due to the unique optical properties of metal nanoparticles, the assembly of metal nanoparticles has attracted wide attention. Metal nanostructures with different chemical compositions, shapes and sizes were assembled precisely to form nanostructures with plasmon resonance effect. These nanostructures exhibit unique circular dichroism, surface-enhanced Raman spectroscopy (SERS) and UV-VIS-UV spectra. These nanostructures with plasmon resonance effect can be widely used in energy collection and biosensor. In previous studies, metal nanostructures were prepared by top-down etching. However, the cost of the method is high, and it is difficult to prepare complex structures such as three-dimensional assembly. Self-assembly technology based on DNA provides a bottom-up rapid assembly method to construct highly coordinated nanostructures. Because DNA nanostructures have the advantages of addressable ability and nanometer resolution, they can be used as templates to assemble metal nanoparticles. In this paper, a unique DNA nanostructure template was designed and synthesized, and various metal nanostructures were formed by assembling different sizes of gold nanospheres onto specific sites of the template by a simple and efficient method. Through the SERS study of the assembled metal nanostructures, it is found that these metal nanoassemblies can effectively enhance the response signals of Raman molecules. Based on the above contents, the research content of this paper is divided into the following three aspects: 1. How to reduce the charge repulsion between the DNA modified gold nanoparticles and the DNA origami template is the key to improve the efficiency of locating and assembling the large size gold nanoparticles on the DNA origami template. We use porous DNA origami as a template to assemble 30 nm gold spheres to form dimer and tetramer structures. The results of transmission electron microscopy (TEM) show that compared with the normal DNA origami template, the assembly efficiency of the nanocrystalline gold ball on the porous DNA origami template is greatly improved. Because gold nanoassemblies have strong surface plasma effect, when Raman active molecules are covalently adsorbed on their surface, Raman signals are greatly enhanced. 2. DNA origami nanostructures mix a long single-stranded DNA with hundreds of short chains. After several hours of annealing assembly, a preset structure is formed. We have designed a novel DNA nanobelts structure, which requires only four DNA chains to be mixed at room temperature in equal proportion for 20 minutes to form micron DNA nanobelts with high yield. The nanobelts can also be used as templates for one-step assembly of gold nanospheres to form long nanocrystalline gold chains. Nanocrystalline gold chains with different sizes (10 nm ~ 20 nm ~ 30 nm in diameter) were assembled by one step method, and the linear arrangement of high density gold spheres produced a lot of hot spots. These nanocrystalline gold chains with plasmonic properties can be used to enhance the SERS signal of Raman molecule. 3. 3. Using DNA nanotechnology, a two-dimensional DNA nanostructure with only five DNA chains was designed to form micron size DNA nanostructures, and the two-dimensional DNA nanostructures were formed by using mica as the surface assistant. In the two-dimensional DNA nanostructures, the special position points extend and capture the DNA chains to assemble the gold nanospheres and form a high-density two-dimensional gold-ball array. This method can be widely used in the fabrication of nanoscale integrated circuits, and the resulting two-dimensional metal nanostructures have great potential as excellent substrates for SERS research.
【學(xué)位授予單位】：南京郵電大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB383.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 Jie Chao;Yinan Zhang;Dan Zhu;Bing Liu;Chengjun Cui;Shao Su;Chunhai Fan;Lianhui Wang;;Hetero-assembly of gold nanoparticles on a DNA origami template[J];Science China(Chemistry);2016年06期

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本文編號(hào)：1820948