導電高分子與離子液體複合修飾網版印刷碳電極對乙醯半胱胺酸之電化學分析

Electrochemical Determination of N-acetyl-L-cysteine at Poly(3,4-ethylenedioxythiophene) and Ionic Liquid Composite Film Modified Screen-Printed Carbon Electrodes

劉子安(Tzu-An Liu)

指導教授 ： 鄭淑華

國立暨南國際大學/科技學院/應用化學系/碩士(2014年)

https://doi.org/10.6837/NCNU.2014.00068

摘要

本研究利用電化學的方式，在水溶液中製備聚(3,4-乙烯二氧吩)(poly-3,4-ethylene-dioxythiophene, PEDOT) 修飾網版印刷碳電極(SPCE)，接著再用旋轉塗佈的方式將離子液體([BMIM+][Cl-])均勻的修飾在電極表面，成功的製備出SPCE/PEDOT/[BMIM+][Cl-]修飾電極。在電化學的應用上，以循環伏安法發現SPCE/PEDOT/[BMIM+][Cl-]修飾電極在pH 7.0環境下偵測N-Acetyl-cystenine (NAC)，分別在0.17 V與0.49 V出現兩個不可逆的氧化峰，而PEDOT修飾電極則只有一個氧化峰在0.49 V，由此推測離子液體修飾電極具有萃取NAC並達到降低NAC氧化電位的效果。此外，也測試其他帶有不同陰離子的離子液體修飾電極(OTf- 、NTf2- 、BF4-、Br-、PF6-)偵測NAC，發現帶有PF6-、Br-的離子液體修飾電極，同樣在0.17 V與0.49 V的地方出現兩個氧化峰。
進一步利用循環伏安法在不同pH值的緩衝溶液中觀察NAC的氧化，發現在pH 7.0時0.17 V的氧化峰會有最大的電流值。用流動注射分析(FIA)，在pH 7.0的PBS下進行NAC的定量工作，其線性濃度範圍為10~600 μM，靈敏度為0.0024 μA/μM，偵測極限(S/N=3)為0.25 μM。

關鍵字

電化學 ； 離子液體 ； 聚(3,4-乙烯二氧吩) ； 乙醯半胱胺酸

並列摘要

In this study, we modified a thin layer of poly-3,4-ethylenedioxythiophene (PEDOT) on a bare screen-printed carbon electrode (SPCE) by electrochemical methods, and then ionic liquid ([BMIM+][Cl-]) was fabricated onto SPCE/PEDOT by spin coating. The obtained SPCE/PEDOT/[BMIM+][Cl-] was employed for the determination of N-Acetyl-L-cystenine (NAC) in pH 7.0 buffer. Cyclic voltammetric studies showed two irreversible oxidation potential of NAC at 0.17 V and 0.49 V. It was suggested that the ionic liquid layer can extract NAC and thus lowered overpotentials. The other ionic liquids with different anions (OTf-, NTf2-, BF4-, Br-, PF6-) were examined for NAC detection, and only Br- and PF6- showed the two oxidation peaks.
Excellent analytical features were achieved by flow injection analysis for determination of NAC under optimized conditions, the linear calibration curve was obtained from 10 μM to 600 μM for NAC and the sensitivity was 0.0024 μA/μM. The detection limit (S/N = 3) was 0.25 μM.

並列關鍵字

electrochemical ； Ionic liquids ； Poly(3,4-ethylenedioxythiophene) ； N-Acetyl-L-cystenine

參考文獻

[1] Safavi, A.; Maleki, N.; Moradlou, O.; Tajabadi, F., Anal. Biochem. 2006, 359, 224-229.

[2] Maleki, N.; Safavi, A.; Tajabadi, F., Anal. Chem. 2006, 78, 3820-3826.

[3] Opallo, M.; Lesniewski, A., J. Electroanal. Chem. 2011, 656, 2-16.

[4] Chang, J.-L.; Wei, G.-T.; Zen, J.-M., Electrochem. Commun. 2011, 13, 174-177.

[5] Wadhawan, J. D.; Schröder, U.; Neudeck, A.; Wilkins, S. J.; Compton, R. G.; Marken, F.; Consorti, C. S.; de Souza, R. F.; Dupont, J. r., J. Electroanal. Chem. 2000, 493, 75-83.