近年來應用質譜儀在蛋白質體的檢測有極大的發展，質譜儀具有快速分析和可提供量化的質荷比等優點。使用矽奈米結構做為承載分析物基材具有高靈敏度、不需使用有機基質和易表面改質等特點，特別適合檢測蛋白質體中之小分子。 本研究主要討論基材表面形貌、孔洞大小與深度對於質譜離子化效率的影響。透過利用金屬輔助化學蝕刻法，藉由不同的蝕刻參數製備出各種表面結構。此外，為了消除干擾分析之背景雜訊，故在進行質譜分析前，將清除這些低質量背景雜訊。而矽奈米結構經由掃描式電子顯微鏡與原子力顯微鏡觀測不同表面結構。質譜測試則藉由表面增強雷射脫附質譜儀測試並將結構表面與對應之質譜數據相互比較後得到： 1.基材蝕刻後低質量區會產生背景雜訊干擾，使用紫外光臭氧清潔儀能降低大部份干擾雜訊。 2.當改變蝕刻時間時，孔洞深度與表面粗糙度會和離子訊號強度成正比。 3.我們發現蝕刻表面矽氫鍵的含量可能為質譜離子化機制的關鍵。 4.以矽奈米結構做為質譜承載樣本基材，確實能應用在檢測小分子毒品標準樣本、經酵素消化後的牛血清白蛋白與人類血清。 In recent years, mass spectrometry has been extensively used as analytical tool in proteomics field. Mass spectrometry can provide rapid analysis and quantify mass to charge ratio. Advantages of using silicon-based nanostructures as substrate material in mass spectrometry analysis include high sensitivity, matrix-free and easy for surface modification. Therefore, silicon-based nanostructure is more suitable in proteomic study for small molecules. In this study, we analyze the effects of substrate structure such as surface morphology, pore size and depth to mass spectrometer ionization efficiency. By controlling the metal-assisted chemical etching process parameters, various silicon nanostructures were produced for the mass spectrometry efficiency test. Besides, in order to eliminate the background noise at low m/z value, the cleaning process prior to mass spectrometry analysis was also investigated. The resulting surface structures were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Mass spectrometry efficiency was characterized by a SELDI-TOF mass spectrometer. By comparing surface structures with mass spectroscopy efficiency result, we found: 1.UV/ozone can reduce most background noise rising from substrate etching. 2.With modification of etching time, the surface roughness and pore depth are positively correlated to ion signal intensity. 3.The quantity of Si-H bond on substrate plays a key role in the mechanism of ionization. 4.Silicon-based nanostructure resembles substrate material can be used to detect drug molecules, enzyme-digested bovine serum albumin and small molecules in human serum.
