Nafion-四硫富瓦烯修饰蜡浸石墨电极的葡萄糖传感器

Amperometric Mediated Biosensor Based on Tetrathiafulvalene -Nafion Chemically Modified Graphite Electrode

本文用四硫富瓦烯(TTF)作为酶与电极之间的电子传递体,通过牛血清白蛋白和戊二醛交联剂,把葡萄糖氧化酶固定在Nafion-TTF修饰石墨电极上,最后在电极修饰一层Nafion膜,制备成葡萄糖传感器。Nafion膜不仅能防止四硫富瓦烯流失,而且能把抗坏血酸、尿酸等电活性物质阻挡在电极外,防止其干扰,同时具有防污性能.通过实验表明TTF^+,TTT^(2+)都能够氧化葡萄糖氧化酶中的辅酶(FADH_2)。该传感器的线性范围为5.0×10^(-4)～1.05×10^(-2)mol/L,响应时间小于30s.

Amperometric mediated biosensor for glucose has been developed by using bovine serum albumin and glutaraldehyde as a cross linker to immobilize glucose oxidase on Nafion-tetrathiafulvalene (TTF) chemically modified graphite electrode. It is further coated by Nafion, which is aqueous solution made of Nafion methanol solution. Inner Nafion membrane can avoid tetrathiafulvalene' s leaking, and prevent electroactive species from oxidizing on the electrode; outer Nafion coating is not detrimental to the enzyme but to further forstall electrochemically active anionic interference such as ascorbate and urate from reaching the electrode and keep the biosensor from fouling agents. It has been experimentally proved that both TTF+ and TTF2+ can oxidize FADH2 of glucose oxidase. The biosensor responds rapidly to glucose in less than 30 s, and its calibration linear curve is from 5. 0×10-4 to 1. 05×10-2 mol/L.