次黃嘌玲之拉曼及表面增強拉曼光譜

The Raman and Surface-Enhanced Raman Spectra of Hypoxanthine

鄭赫文(Ho-Wen Cheng)

指導教授 ： 王玉麟

國立臺灣大學/理學院/物理研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.02398

摘要

目前，許多用以檢測敗血症病患血液中細菌的技術已經被發展完成或正在發展，表面增強拉曼是其中一個正在發展且被認為具有高度潛力能比其他常見技術更迅速完成檢驗的候選技術。根據我們以前的實驗，次黃嘌呤被認為貢獻了格蘭陰性菌如大腸桿菌表面增強拉曼光譜中的幾個主要峰值。此外，次黃嘌呤表面增強拉曼光譜的最大峰值被發現在兩個位置(725 and 743 cm-1)出現。然而，這樣不能解釋的現象會導致以表面增強拉曼光譜來研究格蘭陰性細菌的難度。本論文嘗試發現導致次黃嘌呤的信號改變的原因。我們量測了在固體次黃嘌呤和不同濃度與酸鹼值次黃嘌呤水溶液的拉曼和表面增強拉曼光譜，同時，一些實驗的結果與已密度泛函理論計算次黃嘌呤的拉曼光譜做比較。實驗結果顯示溶液的酸鹼值會影響次黃嘌呤的拉曼及表面增強拉曼光譜，此外，次黃嘌呤的濃度也會影響其表面增強拉曼光譜。這是第一次次黃嘌呤水溶液的拉曼光譜被量到。本研究的發現可以作為增加了解細菌表面增強拉曼光譜的基礎，除此之外，成功的量測次黃嘌呤水溶液在不同酸鹼值的拉曼光譜可以讓未來以拉曼與表面增強拉曼來研究嘌呤衍生物互變異構體得以進行。

關鍵字

拉曼散射 ； 表面增強拉曼散射 ； 次黃嘌呤

並列摘要

Many techniques have been developed or are being developed to identify bacteria of septicemia patients. Surface-enhanced Raman scattering (SERS) is one of the candidates with great potential to achieve the goal at a speed much faster than the conventional method. According to our previous experiments, hypoxanthine (HX) is believed to be responsible for one of the major peaks in the SERS spectra of gram-negative bacteria such as E. Coli. Furthermore, the precise position of this major peak was found to shift (725 and 743 cm-1). This puzzling observation would result in difficulty in the study of gram-negative bacteria by SERS. This thesis tries to find clues that may help resolve the puzzle. Normal Raman and SERS spectra of HX are acquired in solid and solution states with different concentrations and under pH values. Some of the results are compared with normal Raman spectra of HX calculated by density functional theory. The experimental results show that Raman spectra of HX depend on pH values and SERS spectra depend on pH value and concentration. This is the first time that the normal Raman spectra of HX solutions are observed. The findings of this study could serve as a stepping stone for improving our understanding of the SERS spectra of bacteria. Furthermore, the successful acquisition of the normal Raman of HX in aqueous solution under different pH values facilitates the future research of different forms and isomers of purine derivatives via Raman scattering and SERS.

並列關鍵字

Raman scatteringk ； surface-enhanced Raman scattering (SERS) ； hypoxanthine

參考文獻

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