Electrocatalytic Oxidation of Ascorbic Acid and Dopamine at the Self-Assembled Monolayer Modified Screen-Printed Gold Electrodes

• Main Authors: Ming-Chieh Han, 韓明婕
• Other Authors: Shu-Hua Cheng
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/49961367075041610187

碩士 === 國立暨南國際大學 === 應用化學系 === 98 === A monolayer of 2-aminoethanethiol (AET) was modified on a screen-print gold electrode through self-assembly procedure to form AuSPE-AET SAM modified electrode. The modified electrode was confirmed by atomic force microscope (AFM) and electron spectroscopy for chemical analysis (ESCA). The modified electrode was characterized by cyclic voltammetry (CV). The obtained surface coverage (ΓSAM) and double-layer capacitance (Cdl) of the AuSPE-AET SAM were 3.65×10-10 mol/cm2 and 64.38 μF/cm2, respectively. The AuSPE-AET SAM modified electrode was used for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) using differential pulse voltammetry (DPV) in pH7 PBS. A linear calibration plot of AA and DA were 1-1000 μM and 2-1000 μM with the slope of 0.1603 and 0.583 μA/μM, respectively. The detection limit were 0.7 μM. The determination of AA was performed at 0.2 V in a flow injection analysis system with pH 7 PBS as a carrier solution. A linear calibration plot was obtained for 0.01-100 μM AA with the slope of 0.03719 μA/μM. The detection limit was 6.7×10-4 μM. The recovery of AA from the real sample were 94%-102.5%.