- 學位論文
胺基酸於奈米銀的表面增強拉曼散射光譜之增強因子分析
Analysis of the enhancement factors in the SERS spectra of amino acids in silver colloids
摘要
本研究是利用拉曼光譜儀來觀察各種胺基酸分子(半胱胺酸、苯丙胺酸、酪胺酸、色胺酸)及胸腺嘧啶吸附在奈米銀的表面增強拉曼散射效應。當胺基酸分子與奈米銀混合後，因分子的官能基不同會使胺基酸分子吸附在奈米銀表面的位相不同，進而造成拉曼散射強度的差異。為了確定吸附位相的差異是來自於何種官能基的影響，我們在實驗中添加聚合劑和調整溶液pH值，來推測各種胺基酸分子在奈米銀表面的吸附狀態。由計算拉曼增強因子我們發現，添加聚合劑以氟化鉀及磷酸鉀造成胺基酸分子表面拉曼散射效應的增強效果最好。在pH為6.7至10時，胺基酸分子圖譜訊號會有較大的增強效應。在此pH值範圍內添加聚合劑以磷酸鉀的表面拉曼散射效應增強效果最好。所有實驗證據顯示聚合劑陰離子的粒徑大小、帶電荷數、和溶液pH值與增強表面拉曼散射效應有密切的關聯性。
關鍵字
拉曼並列摘要
This study used the Raman spectrometer to observe a variety of amino acid molecules (cysteine, phenylalanine, tyrosine, tryptophan) and thymine adsorbed on the surface of the silver colloids to enhance Raman scattering effect. When the amino acid molecules are mixed with silver colloids, different functional groups of the molecules will cause different orientations of the amino acid molecules when adsorbed on the surface of silver colloids, leading different Raman scattering intensity. In order to determine the functional group that causes the adsorption orientation difference, this study added aggregating agents and adjusted the pH of the solution in the experiments to investigate the adsorption of amino acid molecules on the surface of silver colloids. Calculation of the Raman enhancement factor showed that the addition of aggregating agents, such as potassium fluoride and potassium phosphate, can achieve the best enhancement of amino acid molecule surface Raman scattering effect. When the pH is in the range from 6.7 to 10, amino acid molecular mapping signals have an increased enhancement effect. In this pH range, the addition of potassium phosphate can achieve the best enhancement of surface Raman scattering effect. All experimental evidences showed that the particle size of the anionic aggregating agent, the charge number, and the pH of the solution are closely related to the enhancement of the surface Raman scattering effect.