【作者】 赵英曲；

【导师】 李念兵；

【作者基本信息】 西南大学 ， 物理化学， 2009， 硕士

【摘要】 化学修饰电极是当前电化学、电分析化学方面十分活跃的研究领域,将化学修饰电极用于环境和生命科学现象的研究己是当今化学重要的发展方向之一。纳米微粒具有庞大的比表面积、较强的催化活性和较好的生物相容性等优点,研究过氧化氢及单糖分子在纳米修饰电极的电化学行为是本论文的主要工作之一。该论文的主要研究内容如下:1.过氧化氢在纳米普鲁士蓝/聚L-半胱氨酸修饰电极上的电化学行为研究在铂电极表面制备了聚L-半胱氨酸（p-L-Cysteine,p-L-Cys）/纳米普鲁士蓝（Nanosized Prussian blue,Nano-PB）修饰电极,研究了H₂O₂在该电极上的电化学性质,建立了测定H202的方法。在磷酸缓冲溶液（pH=4.5）中,在1.5×10^-5-1.52×10^-3mol/L范围内,H₂O₂的浓度与还原峰电流呈良好线性关系,相关系数为0.9996;检出限为4.2×10^-7mol/L;达到稳定电流所用时间<9s。实验结果表明:该修饰电极具有制备简单、灵敏度高、响应速度快和抗干扰强等特点.2.过氧化氢在纳米普鲁士蓝修饰铂电极上的电化学行为研究采用静电吸附作用原理,将纳米普鲁士蓝固载在带正电荷的Pt电极上而研制出一种新型过氧化氢（H₂O₂）传感器。采用循环伏安法和计时安培电流法考察了传感器的电化学特性,被吸附的纳米普鲁士蓝对H₂O₂的具有良好的电化学活性,研究结果表明:在优化的实验条件下,该传感器对H₂O₂测定的线性范围为4.0×10^-6mol/L-4.0×10-mol/L,检出限为5.1×10-mol/L。该传感器具有响应快、灵敏度高、制作简便、抗干扰强等特点。3.对巯基苯硼酸/纳米金修饰玻碳电极用于葡萄糖的识别采用自组装技术,将对巯基苯硼酸（MPBA）自组装于带正电荷纳米金（nano-gold,NG）修饰的玻碳电极（GCE）表面,从而制得用于识别葡萄糖的无酶传感器（MPBA/NG/GCE）。通过交流阻抗技术和循环伏安法考察了MPBA/NG/GCE修饰电极的表面电化学特性,同时研究了葡萄糖在该修饰电极上的电化学行为,讨论了利用该修饰电极测定葡萄糖的最佳条件。结果表明:在优化的条件下,氧化峰电流与葡萄糖浓度在1.0-150.0 mmol/L范围内呈良好的线性关系,其回归方程为:.△i_p（μA）:3.37+0.342C（C,mmol/L）,相关系数为r=0.999,检出限为3.8×10^-5mol/L（S/N=3）,可用于葡萄糖分子的电化学识别。4.4-甲酰基苯硼酸/对氨基苯硫酚自组装膜电极对单糖的电化学识别研究采用分子自组装技术,将对氨基苯硫酚（p-ATP）自组装于金电极表面形成一层单分子膜,再通过席夫碱反应,将4-甲酰基苯硼酸（BA）连接在p-ATP单分子层上,构建起BA/ATP/Au电极,通过伏安法和交流阻抗技术研究了修饰电极的电化学特性并讨论了该修饰电极上的端基与葡萄糖,果糖,甘露糖结合的pK_a变化值。研究结果表明,在优化的实验条件下,此传感器在0.1-100.0 mmol/L浓度范围内对各单糖有良好的线性响应,可用于单糖分子的电化学识别。更多还原

【Abstract】 The chemically modified electrode （CME） is currently a very flourish research realm in the electrochemistry and electroanalytical chemistry. The study of CME on environment and life science fields has become one of the most important chemical applications. Nanoparticles have many extraordinary features such as huge specific surface area, strong catalytic activity and good bio-compatibility. Study on the electrochemical behavior of hydrogen peroxide and monosaccharides on the nanoparticles modified electrode is one of the main research works of the thesis, which involves the following subjects:1. Study on the electrochemical behavior of hydrogen peroxide on the Nano-PB/poly-（L-Cys） modified Pt electrodeA novel Nano-PB/poly-L-cysteine film modified Pt electrode was fabricated. The electrochemical properties of hydrogen peroxide （H₂O₂） on the modified electrode were studied and a new method for the determination of H₂O₂ was developed. In the phosphate buffer of pH 4.5, The reduction peak current has a good linear relationship with the H₂O₂ concentration in the range from 1.5×10^-5 to 1.52×10^-3 mol/L with a correlation coefficient of 0.9996. The detection limit was 4.2×10^-7 mol/L （S/N=3）. The time to obtain stable current was below 9 s. The experimental results showed that the modified electrode has the characteristics such as simple fabrication, high sensitivity, rapid response and high selectivity.2. Electrochemical behavior of hydrogen peroxide on prussian blue nanoparticles immobilized platinum electrode 13653405895 A novel hydrogen peroxide sensor was prepared by immobilizing prussian blue nanoparticles on a platinum electrode with positive electrical charge by virtue of the principle of electrostatic adsorption. Cyclic voltommogram and chronoamperometry were employed to study the electrochemical characteristics of the sensor. The immobilized prussian blue nanoparticles exhibited an excellent electrochemical activity toward the reduction of H₂O₂. The experimental results showed that under optimum conditions, the linear range of the sensor for H₂O₂ was 4.0×10^-6 mol/L to 4.0×10^-5 mol/L, and the detection limit was 5.1×10^-7mol/L. The sensor exhibits the features of fast response, high sensitivity, easy fabrication and strong anti-interference ability.3. Recognition of glucose at a glassy carbon electrode modified with 4-mercaptop -henylboronic acid/Nano-gold films.A 4-mercaptophenylboronic acid/Nano-gold film modified glassy carbon electrode （MPBA/NG/GCE） was fabricated based on the self-assemble of MPBA on the surface of glassy carbon electrode modified with gold nanoparticles and its surface electrochemical characteristic was evaluated with cyclic voltammetry and electrochemical impedance spectroscopy. The electrchemical behavior of glucose on the modified electrode has been studied and the optimum conditions for the determination of glucose using this modified electrode were discussed. The results showed that the presence of gold nanoparticles could enhance the electroactivity of glucose at the modified electrode. The current response of MPBA/NG/GCE increased linearly with the glucose concentration in the range of 1.0-150.0 mmol/L with a detection limit of 3.8×10^-5 mol/L （S/N=3）, The linear regression equation is△i_p（μA）=0.337+0.0342C （C, mmol/L） with correlation coefficient of 0.999. This method can be used to the recognition of glucose.4. Electrochemical characterization of in situ functionalized gold p-aminothiophenol self-assembled monolayer with 4-formylphenylboronic acid for recognition of sugarsThe surface of a gold （Au） electrode was modified with p-aminothiophenol （p-ATP） and formed well-packed monomolecular layers through a sulfur-Au bond. Functionalization of ATP/Au self-assembled monolayer with 4-formylphenylboronic acid （BA） via Schiff s base formation, through in situ method to fabricate BA/ATP/Au electrode is presented. Cyclic voltammetry （CV） and electrochemical impedance spectroscopy （EIS） measurements were used to investigate the changes of electrode behavior after each assembly step. The surface pK_a value of the BA/ATP/Au electrode was estimated by CV and EIS. In the presence of sugar, the terminal groups of BA/ATP/Au electrode can react with sugar by forming the phenylboronate esters of sugar on the surface of the electrode and the pK_a values for the BA/ATP/Au electrode in the presence of different sugars （D-glucose, D-fructose, and D-mannose） were also obtained. The fabricated electrode can be used as a novel biosensor for determining sugars on the basis of the change in i_p of the Fe（CN）₆^3-/4- ion in the presence of sugars. The biosensor exhibited excellent performances for determining D-glucose, D-fructose, and D-mannose with low detection limits, wide linear ranges and good sensitivities.更多还原