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基于纳米材料的无酶生物传感器研究

Study of Non-enzymatic Biosensor Based on Nanophase Materails

【作者】 邢亮

【导师】 魏万之;

【作者基本信息】 湖南大学 , 分析化学, 2010, 硕士

【摘要】 纳米科技将引发人类认知和工业的革命。其中,纳米技术在生物传感器上的应用引起了全世界科学家研究的浓厚兴趣。生物传感技术是一个由生物、化学、物理、电子技术等多种学科相互渗透形成的研究领域。生物传感器具有选择性高、分析速度快、操作简易和仪器价格低廉等特点,而且可进行在线甚至活体分析,在临床诊断、环境监测、食品工业等方面得到了高度重视和广泛应用。纳米材料的应用将进一步提高生物传感器的性能,特别是对无酶生物传感器的构建将产生积极和深远的影响,具有广阔的发展前景。本论文利用纳米材料构建和发展了无酶生物传感器,并应用于β-D葡萄糖、H202和NADH的检测。具体研究工作如下:1.Ni(Ⅲ)对葡萄糖有很好的催化氧化功能,能直接氧化葡萄糖为葡萄糖酸内酯。本文采用电沉积的方法在金电极的表面修饰一薄层Ni纳米颗粒,研究发现这种纳米级的镍颗粒比常规镍材料具有更为明显的电催化活性。在0.1mol/L的NaOH溶液中,以0.6 V作为应用电位,测得葡萄糖浓度在10.0μmol/L~2.5 mmol/L范围内呈良好的线性关系,检出限为5.0μmol/L(S/N=3);响应时间为3s。传感器制备简单,无需特殊保管,可重复使用。2.以室温离子液体正辛基-吡啶-六氟磷酸盐(OPFP)代替传统固体石蜡为粘合剂与多壁碳纳米管(MWCNT)、石墨粉相混合制备了一种新型的以多壁碳纳米管修饰的碳离子液体电极(MWCNT-CILE)。优化出制备电极时多壁碳纳米管、离子液体(OPFP)与石墨的比例为1:5:4,以铁氰化钾为电化学探针对碳纳米管/离子液体/石墨复合物电极的电化学行为进行了研究,并与离子液体碳糊电极进行了比较。结果表明由于MWCNT具有很高电催化活性,疏水性的IL(OPFP)有很强的电子传导性能和协同催化作用,使碳纳米管/离子液体/石墨复合物电极对H202和NADH具有更好的电流响应。3.以第3章中构建的多壁碳纳米管修饰的碳离子液体电极(MWCNT-CILE)为无酶葡萄糖传感器在碱性条件下测定葡萄糖浓度。研究表明通过在0.5mol/L的H2SO4中对电极表面的进一步活化,选择在0.1mol/L的NaOH支持电解液中,0.6V的应用电位,测得葡萄糖浓度在50.0μmol/L~8.0 mmol/L范围内呈良好的线性关系,检出限为10.0μmol/L(S/N=3),响应灵敏度高达445.8μAmM-1cm-2;响应时间小于5s。重现性和稳定性良好,对抗坏血酸(AA)和尿酸(UA)具有一定的抗干扰作用,因而具有实际应用于血糖中葡萄糖含量检测的可能。

【Abstract】 Nanotechnology will become a revolution of human cognition and the industrial. Herein, nanotechnology applied in biosensor has caused the study interest of scientists over the world. Biosensors have developed to be a frontier and newly-interdisciplinary including chemistry, biology, physics and electronics. Due to its simplicity, high sensitivity and potential ability for real-time and on-site analysis, biosensors have been widely applied in various fields including clinical diagnosis, environment monitoring, food control and industrial process and so on.The application of nanometer materials will further improve the performance of biosensors, especially produce positive and far-reaching influence for non-enzymatic biosensors, and has a broad development prospects.The main work of this paper focuses on using nanometer material to fabricate and develop non-enzymatic biosensors, and applying their novel biosensors to detect p-D Glucose,H2O2 and NADH. The main points of this thesis are summarized as follows:1. The Ni (Ⅲ) had a good function for catalytic oxidation of glucose, which could oxidate glucose to glucolactone directly. A thin film of Ni nanoparticles modified electrode has been fabricated by electrodeposition. It was found that the Ni nanoparticles showed obvious electrocatalytic activity than conventional Ni materials. The modified was used to detection glucose at 0.6V in 0.1mol/L NaOH solution, the response current was good proportional to the concentration of glucose over the range 10.0μmol/L~2.5 mmol/L, with a detection limit of 5.0μmol/L(S/N= 3) and a response time of 3s. The preparation of the sensor is simple and has a lower cost, as well as can be used repeatedly.2. A new kind of room temperature ionic liquid (n-octylpyridinum hexafluorophosphate,OPFP) mixed with multiwall carbon nanotubes(MWCNT) and graphite powder composite eletrode was constructed based on the substitute of the paraffin oil. The optimal condition for preparation was selected as 1:5:4(mass ratio) for MWCNT, OPFP and graphite powder. The electrochemical behaviors of the MWCNT/IL/graphite composite electrode(MWCNT-CILE) was investigated by using K3 [Fe (CN) 6] as probe and compared with IL(OPFP)/graphite electrode(CILE) as mass ratio of 5:5. The result indicated that the novel composite electrode had a better response to H2O2 and NADH than CILE due to the high catalytic performance of MWCNT and the strong electronic transmission performance and collaborative catalysis of OPFP.3. Using the MWCNT/IL/graphite composite electrode(MWCNT-CILE) fabricated in Chapter 3 as a non-enzymatic glucose biosensor detect the concrntration of glucose in alkaline medium. It was observed that the novel composite electrode showed a higher response current to glucose after further oxidation in 0.5 mol/L H2SO4. Under the optimized condition, glucose was determined by chronoamperometry in in 0.1 mol/L NaOH supporting electrolyte at applied potential of 0.6V, the calibration curve is linear in the concentration range of 50.0μmol/L~8.0 mmol/L with a detection limit of 10.0μmol/L(S/N=3) and excellent sensitivity of 445.8μAmM-1 cm-2; the response time is less than 5 seconds. The non-enzymatic glucose biosensor exhibited fine reproducibility and stability. In addition, the biosensor can eliminate interference from ascorbic acid(AA) and uric acid(UA). Thus it has a practical application probable in detecting the blood sugar levels of glucose.

  • 【网络出版投稿人】 湖南大学
  • 【网络出版年期】2011年 03期
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