碳纳米管负载铂修饰电极结合溶胶-凝胶技术制备胆固醇传感器

A Cholesterol Biosensor Based on Cholesterol Oxidase Immobilized in a Sol-gel on a Platinum-decorated Carbon Nanotubes Modified Electrode

制作了碳纳米管和碳纳米管负载铂镶嵌修饰的浸蜡石墨电极,实验发现纳米铂的引入使修饰电极对过氧化氢的还原有更好的电催化性能.用溶胶-凝胶法将胆固醇氧化酶固定在碳纳米管负载铂修饰的浸蜡石墨电极表面,构建了一种新型的胆固醇生物传感器.实现了低电位下对胆固醇的间接测定.胆固醇浓度在4.0×10-6～1×10-4 mol/L范围内与其峰电流的增量呈现良好的线性关系.检出限为1.4×10-6 mol/L.该传感器的灵敏度高,选择性好,可以避免样品中大量易氧化物质的干扰,且寿命长,性能稳定.

Modified electrodes were constructed by intercalating carbon nanotube or platiumn-decrated carbon nanotube on graphite electrodes surface. The results show that nano-particles of platinum exhibited high activity and selectivity in the detection of hydrogen peroxide. An amperometric cholesterol biosensor was prepared by immobilizing of cholesterol oxidase ( ChOx) in sol-gel on a platinum-decorated carbon nanotubes modified electrode. The experiments show that nanoparticles can enhance the catalytic activity of the immobilized enzyme. The linear detection range is 4.0 x 10(-6) similar to 1 x 10(-4) mol/L and the detection limit is 1. 4 x 10(-6) mol/L. The configuration ( ChOx/Sol-gel/CNT-Pt) of the biosensor greatly limits the interference of some biocompounds, which are easily oxidizable and adsorbed on electrode surface.