聚咖啡酸薄膜修飾電極對沒食子酸之電化學分析

Electroanalytical determination of gallic acid at poly(caffeic acid) film-modified electrodes

朱啟安(Chi-An Chu)

指導教授 ： 鄭淑華

國立暨南國際大學/科技學院/應用化學學系/碩士(2016年)

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，再將咖啡酸(Caffeic acid, CAF)薄膜以循環伏安法 (Cyclic voltammetry, CV)方式修飾至碳電極表面，即成功製備聚合咖啡酸薄膜修飾電極(SPCE*-PCAF)。以 SPCE*-PCAF為工作電極，進行沒食子酸(Gallic acid, GA)分子的電化學檢測分析。先將SPCE*-PCAF浸泡至 GA 溶液中，讓GA吸附電極上直接於原溶液中進行循環伏安法掃描。由實驗結果發現SPCE*-PCAF比bare SPCE更可使 GA 氧化訊號大幅增加，並由結果推測電極經過氧化處理後，電極反應面積增加，且電極表面有導電的聚合咖啡酸薄膜，可使GA氧化電流訊號有增幅的效果。實驗條件最佳化後，發現GA於pH 3的水溶液下吸附可得到最佳的氧化電流值，GA分析是以差式脈衝伏安法 (Differential Pluse Voltammetry, DPV) 進行定量，此方法的靈敏度為 7.394A/M，線性範圍介於 0.1M-20M，偵測極限為0.061M (S/N=3)。

關鍵字

網版印刷碳電極 ； 咖啡酸 ； 沒食子酸 ； 吸附 ； 差式脈衝伏安法

並列摘要

In this study, we prepared an overoxidized screen-printed carbon electrode (SPCE*) immobilized with a thin electroactive poly(caffeic acid) (PCAF) film by cyclic voltammetry (CV), and the modified electrode was used for determination gallic acid (GA). The SPCE*-PCAF could adsorb GA strongly because the PCAF film containned highly abundant oxygen functionality. The SPCE*-PCAF was immersed in GA solution for 15 minutes, and then CV scan was operated in the same solution. The oxidation current responses increase significantly at SPCE*-PCAF as compared with bare SPCE.
Under optimal differential pulse voltammetry (DPV) conditions, the proposed assay can be used to sense GA in pH3.0 buffer. The method sensitivity was 7.394A/M, and exhibited a linear response to GA in the range of 0.1-20 M. The detection limit was 0.061M (S/N=3).

並列關鍵字

screen-printed carbon electrode ； caffeic acid ； gallic acid ； adsorption ； differential pulse voltammetry

參考文獻

[1] Y. Liang, W. Cao, W.-j. Chen, X.-h. Xiao, J.-b. Zheng, Simultaneous determination of four phenolic components in citrus honey by high performance liquid chromatography using electrochemical detection, Food Chemistry, 114 (2009) 1537-1541.

[2] G. Zhao, J. Gao, S. Shen, M. Liu, D. Li, M. Wu, Y. Lei, Ultrasound enhanced electrochemical oxidation of phenol and phthalic acid on boron-doped diamond electrode, Journal of Hazardous Materials, 172 (2009) 1076-1081.

[3] M.M. Davila Martin Marino, F. Ahuatl, M. Elizalde, J. Mattusch, R. Wennrich, Electrochemical Detection of Polyphenolic Compounds Using Carbon Composite Electrodes, ECS Transactions, 3 (2006) 69-80.

[4] J. Adamski, J. Kochana, P. Nowak, A. Parczewski, On the electrochemical biosensing of phenolic compounds in wines, Journal of Food Composition and Analysis, 46 (2016) 1-6.

[5] F.W. Kong Wei-Bao, Lu Jian, Zhao Hai-Feng,Dong Jian-Jun, Shan Lian-Ju, Lin Yan, Changes of Phenol ic Compounds and Related Enzymes during Barley Malting, Journal of Food Science and Biotechnology, 26 (2007) 61-85.