Quantum dots have applications in biomedical fields such as bio-imaging and drug delivery systems. This thesis describes research on silicon and germanium nanoparticles (quantum dots) synthesis and surface modification for biological applications. Purification methods of these quantum dots were also explored. In chapter 6 the application of silica nanoparticles into dry eye diagnosis was studied. The purpose of this research is to contribute the application of nanotechnology into biological fields. The crystalinity of the quantum dots was characterised by Transmission Electron Microscopy (TEM) and Selected Area Electron Diffraction analysis (SAED). The molecules on the surface of the quantum dots were characterised by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR).Silicon quantum dots were synthesised with a microemulsion system and various types of molecules were attached on the surface of the silicon quantum dots. However, some of the capping molecules which have oxygen atoms tend to form bonds between oxygen and silicon. Therefore, in the later chapter (chapter 4) various chemical reactions were conducted on the molecules attached to the silicon quantum dots. The silicon quantum dots were capped with diene molecules and one of the double bonds was left on the terminal end. The terminal end double bonds were converted to the functional groups which contain oxygen atoms to form peptide bonds. In this way it was confirmed that it can reduce the risk of oxygen atoms to be attached on the surface of the silicon quantum dots. The molecules on the surface of the silicon quantum dots were characterised mainly by FTIR and ¹H NMR. Optical properties and cyto-toxicity of these silicon quantum dots were also measured and analysed depending on the surface molecules.Two synthetic approaches were taken to produce germanium quantum dots. The first approach was the microemulsion system at room temperature. Different combinations of the surfactant and capping molecules were tested. For the second approach, high temperature bench top system was applied. In this method the bio-friendly molecules which have high boiling points were chosen as capping agents. The surface molecules were characterised by FTIR spectroscopy.In chapter 6 the synthesis of dye molecules conjugated silica nanoparticles was described. The purpose of this research is to produce biologically safe nanoparticles which can be applied in dry eye diagnosis. Three different dyes were used to conjugate with the silica nanoparticles. Only fluorescein isothiocyanate (FITC) succeeded in conjugating with the nanoparticles. Optical properties of this sample were measured and compared with the free dye molecule. Also the sample was applied in human eyes to analyse the tear film layer.An overall conclusion and future plans for the research were given in the last chapter.In this chapter, ideas of overcoming the problems and improving the techniques conducted in the research were described.
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机译：量子点已应用于生物医学领域，例如生物成像和药物输送系统。本文介绍了用于生物应用的硅和锗纳米粒子（量子点）的合成和表面改性的研究。还研究了这些量子点的纯化方法。在第六章中，研究了二氧化硅纳米颗粒在干眼症诊断中的应用。这项研究的目的是促进纳米技术在生物领域的应用。量子点的结晶度通过透射电子显微镜（TEM）和选择区域电子衍射分析（SAED）进行表征。通过傅立叶变换红外光谱（FTIR）和核磁共振（NMR）表征量子点表面上的分子，并通过微乳液系统合成硅量子点，并将各种类型的分子附着在硅量子表面上点。然而，一些具有氧原子的封端分子倾向于在氧和硅之间形成键。因此，在下一章（第4章）中，对附着在硅量子点上的分子进行了各种化学反应。硅量子点被二烯分子覆盖，双键之一留在末端。将末端双键转变成含有氧原子的官能团以形成肽键。以此方式证实了可以减少氧原子附着在硅量子点的表面上的风险。硅量子点表面的分子主要通过FTIR和1 H NMR表征。还根据表面分子对这些硅量子点的光学性质和细胞毒性进行了测量和分析。采用两种合成方法生产了锗量子点。第一种方法是在室温下使用微乳液体系。测试了表面活性剂和封端分子的不同组合。对于第二种方法，应用高温台式系统。在这种方法中，选择具有高沸点的生物友好分子作为封端剂。通过FTIR光谱对表面分子进行了表征。在第六章中，描述了染料分子共轭二氧化硅纳米粒子的合成。这项研究的目的是生产可用于干眼症诊断的生物安全纳米粒子。三种不同的染料用于与二氧化硅纳米颗粒共轭。只有异硫氰酸荧光素（FITC）成功与纳米粒子结合。测量该样品的光学性质，并将其与游离染料分子进行比较。最后一章给出了研究的总体结论和今后的计划。在这一章中，描述了克服问题和改进研究技术的想法。 。
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