【作者】 阎博；

【导师】 赵新华； 赵林；

【作者基本信息】 天津大学 ， 环境科学， 2005， 博士

【摘要】 生物传感器是一门新兴交叉学科,在环境监测、生物医学、食品分析、军事等领域有重要应用价值。生物传感器的性能优劣很大程度上取决于生物分子的固定化效果。在生物传感器所用的生物分子固定化材料中,基于溶胶-凝胶方法的有机-无机杂化材料由于具有一系列优点而成为一种理想的固定化材料。本文通过合成新型有机-无机杂化材料制备了葡萄糖氧化酶电极和硝酸还原酶电极,研究了其电化学性质,同时对葡萄糖氧化酶电极进行了一系列的改良。论文包括以下几个部分内容:通过酯化反应在聚乙烯醇高分子链上接枝上了部分巯基,得到了一种新型高分子接枝物,将此接枝物与二氧化硅溶胶-凝胶结合制备了一种新型的有机-无机杂化材料。由于杂化材料表面的巯基和金电极表面形成了配位键,此杂化材料薄膜在金电极表面上有很强的附着力。以此杂化材料作为固定化介质,在金电极上制备了葡萄糖氧化酶电极。此酶电极的响应电流为0.6μA/mM,响应速度只有1.8秒。在连续测量,酶电极的响应电流在11个小时以后只下降了10.3%。间隔使用的情况下,响应电流在两个月内没有明显的变化。以此杂化材料和铂电极结合制备了一种葡萄糖氧化酶电极,由于铂对过氧化氢的催化作用,此酶电极可以在0.05V下工作的,具有很强的抗干扰性。将普鲁士蓝电沉积到杂化材料的多孔结构中,制备了普鲁士蓝修饰电极。在此修饰电极上制备成了一种新型的葡萄糖氧化酶电极。此酶电极可以在-0.05V下进行葡萄糖的测定,间歇使用的情况下,22天后响应电流为初始值的92%,具有很好的稳定性。此酶电极的响应速度为4秒左右。研究了纳米银粒子和碳纳米管的掺入对葡萄糖氧化酶电极性能的影响。结果表面:纳米银粒子掺杂的酶电极的线性范围增大了4倍,达到了40mM,最大检测范围为140mM左右。碳纳米管则可以将酶电极的工作电位降到0.18V。同时两种酶电极的响应速度分别为3.4秒和3秒。硝酸盐是水体中的一项重要的污染质,快速准确地测定硝酸盐具有重要的意义。本文首次构建成功了一种基于有机-无机杂化材料的电流型硝酸还原酶电极,其工作电位为-0.68V,以甲基紫精为电子媒介体。此酶电极21天后响应电流的绝对增量为初始绝对增量的85.7%,具有较好的稳定性。更多还原

【Abstract】 Biosensors are new analytical tools with the merits of selectivity, fast responding, low operation expense et al, and they have been applied into environment monitoring, clinical diagnosis, food quality control and military medicine. Sol-gel derived hybrid material have become one of the most appropriated enzymes immobilized matrix. In this thesis, a new sol-gel derived material has been composed and several glucose oxidase biosensors and a nitrate reductase biosensor have been fabricated. The electrochemistry characters of the biosensors have been studied, and lots of work has been done to enhance the performance of the glucose biosensors. The detailed work of this thesis has been set out as follows:A new graft polymer was composed by esterification reaction between Poly (vinyl alcohol) and mercaptoethylamine. Based on this graft polymer and sol-gel, a new organic-inorganic hybrid material had been obtained. The characters of the new graft polymer and hybrid material have been studied, and the parameters of hybrid material preparation have also been optimized.Based on this hybrid material, glucose oxidase was embedded and immobilized on surface of gold electrode to fabricate a new type of glucose biosensor. The enzymes embedded in the hybrid material showed high activity due to the great deal of hydroxide radical and hydrogen bonds of the hybrid material, The great deal mercapto group of the graft polymer can help the hybrid material membrane to be adsorbed onto gold surface tightly, so the biosensors based on this hybrid material have excellent stability. At the same time, the biosensor has many merits such as fast response, great response current and low detect limit.Based on this hybrid material and platinum electrode, a new type of glucose biosensor had been fabricated. This biosensor can work at a low potential (0.05V) so its antidisturbance performance was excellent.We have also fabricated a biosensor with the hybrid material and electrodeposited Prussian blue, this biosensor can work under–0.05V by reduction of the H2O2 produced by enzymes reaction. The low working potential can help to enhance the biosensor’s interference immunity, so the biosensors have good practical value. After 21 days interval use, the response current dropped to 92% of its initial value. The response time of the biosensor was about 4s.To enhance the performance of the biosensors, silver nanoparticles and carbonnanotubes were added into the hybrid material. The result showed that the silver nanoparticles can extend the linearity range by 4 times and the carbon nanotubes can reduce the operating potential from 0.65V to 0.18V (vs SCE). The response time of the two biosensor were about 3.4s and 3s.Nitrate is a very important contamination of water, so the detection of nitrate by a fast and accurate method is of great value. In this thesis, the first amperometric nitrate reductases biosensor based on sol-gel derived hybrid material was fabricated. The nitrate biosensor showed good stability by 85.7% response current retained after 21 days. To our knowledge, this is the first amperometric nitrate reductase biosensor based on sol-gel materials.更多还原