本研究將探討利用半胱胺(cysteamine)修飾之SERS基板作為酸鹼值感測器的可能性，並應用於尿液的拉曼檢測。
本研究包含兩個部分，第一部分製備銀奈米立方體顆粒與銀基板，藉由自組裝單分子層技術將銀奈米粒方體自組裝於銀金屬薄膜上，利用半胱胺修飾SERS基板後，接續進行相關的性質分析。由紫外光/可見光光譜分析得知以不同半胱胺濃度修飾基板表面後，會使SERS基板的表面電漿共振(SPR)波長產生位移，影響SERS基板的拉曼增顯能力。藉由分析SERS基板拉曼訊號的特徵峰變化，得到拉曼訊號與酸鹼值變化的關係，預期能作為有效的酸鹼值感測器。
第二部分將製備完成的半胱胺修飾之SERS基板應用於尿液的酸鹼值測定，由拉曼實驗所得到的酸鹼值與酸鹼度計得到的酸鹼值誤差範圍在3%以內，代表半胱胺修飾之SERS基板可做為有效的酸鹼值感測器。最後利用低濃度亞甲藍(methylene blue)的拉曼量測得知半胱胺修飾之SERS基板的偵測極限，約為10-10M。

Surface-enhanced Raman scattering (SERS) substrates with massive hotspots on a large scale from nanogaps can be fabricated by self-assembling silver nanocubes on massed silver mirror via 1, 2-ethanedithiol monolayer as linkage. By using cysteamine to modify the SERS substrate, it can successfully reflect the pH of complex environment and be proven as a pH sensor in a real biological environment such as human urine. By analyzing the variation of Raman signals of cysteamine-modified nanoplasmonic SERS substrate, it is easy to get a good and wide linear response to pH ranging from 3.47 to 10.38. It is found that the results obtained by the SERS analysis are similar (<3%) to pH meter, and the relative standard deviation (RSD) values are below 4.2%. The results of UV-Vis analysis show that the modifications of cysteamine will shift the surface plasmon resonance (SPR) wavelength from a longer one to a shorter one. Therefore, there exists a specific concentration of cysteamine to modify the SERS substrates which can make the UV-Vis absoption peak properly match to 633nm Raman laser thus greatly enhance its SERS signals. Raman results prove the good performance of cysteamine-modified nanoplasmonic SERS substrate by detecting 10-10 M methylene blue solution with high sensitivity. This work not only emerges a rapid, easy, and low-cost way to fabricate nanostructured SERS substrates but also largely expands its functionality.

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