Electrocatalytical oxidation of hydroquinone with ferrocene covalently bound to L-cysteine self-assembled monolayers on a gold electrode.
The preparation of a gold electrode modified by ferrocenecarboxylic acid (FcA) covalently bound to L-cysteine self-assembled monolayer (FcA-SAM) is described. The modified electrode shows an excellent electrocatalytic activity for the oxidation of hydroquinone (QH2) and accelerates the electron transfer rate. The anodic overpotential is reduced by ca. 290 mV compared to those obtained at bare gold electrodes. The charge transfer coefficient and the apparent surface electron transfer rate constant for the redox couple of Q/QH2 at the modified electrode are found to be 0.425 and 0.96 s(-1), respectively. The catalytic current response of DPV increases linearly with the QH2 concentration from 5.7 x 10(-7) to 3.2 x 10(-4) M. The estimation of QH2 in a simulative sample is satisfactory. The method is simple, quick, and sensitive.
Kan
Xian-wen
XW
School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China. xianghuideng@yahoo.com.cn
Deng
Xiang-hui
XH
Zhang
Wen-zhi
WZ
Wang
Guang-Feng
GF
Li
Mao-guo
MG
Tao
Hai-sheng
HS
Fang
Bin
B
D002384:Catalysis; D003545:Cysteine / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006873:Hydroquinones / Q000737:chemistry*; D000075163:Metallocenes; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity
D005296:Ferrous Compounds; D006873:Hydroquinones; D000075163:Metallocenes; C032949:ferrocenecarboxylic acid; D006046:Gold; D003545:Cysteine; C004998:ferrocene; C031927:hydroquinone