Antioxidant Sensors Based on Iron Diethylenetriaminepentaacetic Acid, Hematin, and Hemoglobin Modified TiO2 Nanoparticle Printed Electrodes

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• 作者：Qingqing Guo ; Shujun Ji ; Qiaoli Yue ; Lei Wang ; Jifeng Liu ; Jianbo Jia
• 刊名：Analytical Chemistry
• 出版年：2009
• 出版时间：July 1, 2009
• 年：2009
• 卷：81
• 期：13
• 页码：5381-5389
• 全文大小：295K
• 年卷期：v.81,no.13(July 1, 2009)
• ISSN：1520-6882

文摘

Antioxidant amperometric sensors based on iron-containing complexes and protein modified electrodes were developed. Indium tin oxide glass was printed with TiO₂ nanoparticles, onto which iron-containing compounds and protein were adsorbed. When applied with negative potentials, the dissolved oxygen is reduced to H₂O₂ at the electrode surface, and the H₂O₂ generated in situ oxidizes Fe^II to Fe^III, and then electrochemical reduction of Fe^III therefore gives rise to a catalytic current. In the presence of antioxidants, H₂O₂ was scavenged, the catalytic current was reduced, and the decreased current signal was proportional to the quantity of existing antioxidants. A kinetic model was proposed to quantify the H₂O₂ scavenging capacities of the antioxidants. With the use of the sensor developed here, antioxidant measurements can be done quite simply: put the sensor into the sample solutions (in aerobic atmosphere), perform a cathodic polarization scan, and then read the antioxidant activity values. The present work can be complementary to the previous studies of antioxidant sensor techniques based on OH radicals and superoxide ions scavenging methods, but the sensor developed here is much easier to fabricate and use.