- 學位論文
苯磺胺薄膜修飾電極的製備及鳥嘌呤之電化學分析應用
Preparation of Sulfanilamide Film-modified Electrodes for the Electrochemical Determination of Guanine
摘要
本研究先將網版印刷碳電極(Screen-printed carbon electrode, SPCE)進行過氧化處理(SPCERD)，最後將苯磺胺(Sulfanilamide, SAA)以循環伏安法(Cyclic voltammetry, CV)方式修飾至電極表面，即成功製備苯磺胺薄膜修飾電極(SPCERD/dimer(SAA))。SPCERD/dimer(SAA)浸泡至鳥嘌呤(guanine)溶液中，使guanine吸附至電極上後，直接於原溶液中進行循環伏安法掃描。由實驗結果發現，未經處理的電極並沒有辦法將苯磺胺薄膜固定在電極上，而將過氧化處理後浸泡修飾上苯磺胺薄膜的SPCERD/dimer(SAA)im電極與電雙合修飾上處理方式相比， SPCERD/dimer(SAA)更可使guanine氧化訊號大幅增加，推測電極經過過氧化及電雙合修飾苯磺胺分子處理後，電極反應面積增加，且電極表面修飾材料與鳥嘌呤之間作用力增強，可使鳥嘌呤氧化電流訊號有增強的效果。二聚苯磺胺薄膜在SPCERD電極上能觀察到明顯的氧化還原峰。修飾電極的表面形貌、元素組成和親疏水性等特性以原子力顯微鏡（AFM），掃描電子顯微鏡（SEM），光電子能譜（XPS）和水接觸角等技術得到驗證。鳥嘌呤分析是以差式脈衝伏安法 (differential pulse voltammetry, DPV)進行定量，此方法的靈敏度為 51.02 A/M，線性範圍介於 0.5-10 M，偵測極限為1.18 nM (S/N=3)。
並列摘要
In this study, a screen-printed carbon electrode (SPCE) was overoxidized (SPCERD) and then immobilized with a thin electroactive sulfanilamide film (dimer(SAA)) by cyclic voltammetry (CV), and the dimer(SAA) film modified electrode was successfully prepared (SPCERD/dimer(SAA)). The characteristics of the dimer film-modified electrodes were well-characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), photoelectron spectroscopy (XPS) and the water contact angle technique. Electrochemically induced dimerization mechanisms were discussed. The as-prepared modified electrode was used for the sensitive determination of guanine by immersing the sensor in solution for 15 minutes to adsorb guanine viaπ-π stack and hydrogen bonding interaction. The dimer(SAA) film cannot be modified on bare electrode. The guanine oxidation current responses were larger at SPCERD/dimer(SAA) as compared with SPCERD electrode immersed in SAA solution for 10 minutes. Under the optimal differential pulse voltammetry (DPV) conditions, the method sensitivity was 51.02 A/M. A linear response to guanine in the range of 0.5-10 M was obtained. The detection limit was 1.18 nM (S/N=3).