"開發聚(3,4-乙烯二氧噻吩)/氧化石墨烯修飾之電極作為美沙拉秦電化學感測應用"

Abstract

本研究利用聚3,4-乙烯二氧噻吩(poly(3,4-Ethylenedioxythiophene), PEDOT)與氧化石墨烯(graphene oxide, GO)來修飾玻碳電極，並利用循環伏安法和微分脈衝伏安法等電化學方法在此修飾後的電極上偵測美沙拉秦。相較於未修飾的玻璃碳電極，所有經過聚3,4-乙烯二氧噻吩修飾的玻璃碳電極都顯示出對美沙拉秦的電流響應有顯著的增強效果，這是因為聚3,4-乙烯二氧噻吩具帶正電荷的主鏈可以吸引帶有負電荷的美沙拉秦。此外，我們發現與其他pH值和緩衝液相比，當美沙拉秦在pH 6.0的磷酸鹽緩衝溶液中做電化學偵測時會在氧化電位 +0.22 V處產生最高的氧化峰值電流。最後，與PEDOT/GC和PEDOT-GO修飾的玻璃碳電極相比，PEDOT/GO表現出最大的美沙拉秦氧化峰電流增加，且美沙拉秦的氧化峰電流值會隨濃度在0.01 mM到1.00 mM的範圍線性增加，校準方程為y = 21.94x + 0.01（R^2 = 0.971），偵測極限為10 μM。為了進一步證明PEDOT/GO修飾的玻璃碳電極的應用性，我們還在維生素C、尿酸以及人類血清蛋白的干擾下對MES進行微分脈衝伏安法測量。

A simple electrochemical method was investigated for the detection of mesalazine (MES) on three kinds of poly(3,4-ethylenedioxythiophene) (PEDOT) and graphene oxide (GO)-modified glassy carbon electrode (GCE) by both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Compared with bare GCE, the PEDOT-modified GC electrodes shows a significant enhancement in the current responses for MES due to the positively charged backbones of PEDOT, which can attract the negatively charged MES. Moreover, we found the oxidation of MES reached a maximum current at + 0.22 V vs Ag/AgCl in PBS at pH = 6.0 compared in other PBS buffer at other pH values. Finally, PEDOT/GO/GC electrode presented the best MES detection performance and showed the greatest increases in MES oxidation current compared among all the modified GC electrodes. The oxidation current increased linearly with the MES concentration from 0.01 mM to 1.00 mM with a calibration equation of y=21.94x+0.01 (R^2 = 0.971), and the limit of detection is 10 μM. To demonstrate the application of the PEDOT/GO/GC electrode, we applied the DPV measurement of MES in the presence of three interferences, including ascorbic acid, uric acid and human serum albumin, respectively.