TERS和SERS於醣類分子與二茂鐵基底藥物分析之應用

Abstract

這份論文主要會分為四個章節：第一章會概要介紹表面增強拉曼散射 (Surfaced-Enhanced Raman Scattering, SERS)和尖端增強拉曼散射 (Tip-Enhanced Raman Scattering, TERS)。我們將簡要回顧SERS和TERS的發展和應用的相關文獻。在研究中使用的所有化學藥品和實驗流程會在第二章中描述。 在第三章的第一部份，我們會探討發展以SERS為基礎，針對醣類的靈敏度以低樣品體積分析方法之可能性。這是和中正大學化生系游景晴老師合作的計畫，由游老師提供不同類型的寡聚醣作為我們的研究材料。我們發現SERS是一項靈敏的技術，能夠分辨由酵素合成的不同寡聚醣結構關係。這開啟了理解醣類合成機制新的研究方式。 在第三章的第二部份，我們記述結合有機金屬分子的TERS探針之製備，也展示了有機金屬化學領域與TERS技術的完美結合可應用於雙重分子的訊號偵測。由有機金屬分子所產生的獨特拉曼訊號可以避開來自血液中生化分子的干擾，因而讓對兩個重要指標分子(葡萄糖和硫醇)在極低樣品需求量 (50 nL)下進行快速分析變得可行。這建立起在血液中葡萄糖和硫醇的含量對糖尿病患者與否的關聯性研究潛力。 在第三章的第三部份，我們描述一個新方法能夠直接量測Ferrocifen (Fe-Tam；一種以二茂鐵為基底的藥物)在細胞中的反應中間體。解明其抗增殖行為具有重大意義，能夠幫助合理設計有更有效機制的新穎化療藥物，以及開發化學方法以避免特定抗藥性機轉。在實驗中，可以觀察到明確的振動特徵訊號代表二茂鐵基醌甲基化物 (Fe-Tam-QM)於細胞內的生成以及其進一步和細胞中親核試劑之反應。由我們的合作者中研院化學所江明錫老師與朱愷悌博士協助密度泛函理論計算 (density functional theory, DFT)，證明了振動模式的改變來自於不同二茂鐵基相關之結構。以上結果啟發了對二茂鐵基藥物的完整了解和開發更多金屬基底之治療藥物的可能性。 在第四章，我們列出這份研究工作中的主要結論。此外，我們也討論這份工作遇到的限制和失敗，強調這領域中未來的研究方向。

The thesis is divided into four chapters. Chapter 1 gives a brief introduction to surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS). Literature reports on development and applications of SERS and TERS are discussed in brief. All the experimental and chemicals used in this projects are listed in chapter 2. In first part of chapter 3, we discuss our exploration of the possibility of development of SERS-based sensitive technique with ultra-low volume for carbohydrates. This is a collaboration project with Prof. Ching-Ching Yu in National Chung Cheng University (Department of Chemistry and Biochemistry). Prof. Yu provided different types of oligosaccharides in our study. Our findings show that SERS is a sensitive technique that is able to characterize the structure-property relationship of oligosaccharides synthesized by enzymes which opens a new way to realize mechanisms of carbohydrates synthesis. In second part of chapter 3, we report the preparation of an organometallic-conjugated TERS tip. We demonstrate that organometallic chemistry can be perfectly coupled with TERS for dual-molecule sensing. The unique Raman signals generated by the organometallic compound circumvent signal interference from the biomolecules in blood, allowing the rapid analysis of two important molecules (glucose and thiol) in ultralow volume (50 nL) samples. This enabled a correlation between the thiol and glucose levels in the blood of nondiabetic and diabetic patients to be drawn. The third part of chapter 3 describes a method that can directly detect intermediates of ferrocifen (Fe-Tam; a ferrocene-based drug) in cells which is of paramount importance to unravel their anti-proliferative action that rationally design new chemotherapy drugs with a more effective mechanism of action and develop chemical strategies to circumvent specific drug resistance mechanism. In the experiment, distinct vibrational features are observed for the formation of ferrocenyl quinone methide (Fe-Tam-QM) in cellular and toward reacts with cellular nucleophiles. DFT calculations from our collaborators (Prof Ming-Hsi Chiang and Dr Kai-Ti Chu) in Institute of Chemistry of academic sinica show the observed vibrational mode changes is resulted in the different configuration of ferrocenyl-related modes. These results shed light on the full understanding of the ferrocenyl-based medicine and developing more advanced metal-based therapy agents. In chapter 4, we list out the major conclusions arrived at in this work. In addition, we discuss the limitations and major failures of this work and highlight the scope for future research in this area.