【作者】 边秀珠；

【导师】 李念兵；

【作者基本信息】 西南大学 ， 物理化学， 2010， 硕士

【摘要】 自从1978年首次用电沉积的方法将普鲁士蓝修饰到电极表面以来,普鲁士蓝在传感器方面得到了广泛的应用。但传统的普鲁士蓝修饰电极在中性偏碱性溶液中不稳定、易溶解,大大限制了其应用价值。所以研究者通过高分子聚合膜将普鲁士蓝固定在电极表面,提高了普鲁士蓝在碱性溶液中的稳定性,同时也改善了传感器的性能。另外,近年来使用过渡金属离子代替普鲁士蓝中的部分铁离子,合成含过渡金属的类普鲁士蓝配合物正在成为研究的热点。本论文中,我们首先利用聚二烯丙基二甲基氯化铵和壳聚糖作为稳定剂合成了普鲁士蓝纳米溶胶；接着用铈离子代替部分铁离子,合成了铈掺杂的类普鲁士蓝纳米溶胶。实验中采用透射电镜(TEM)、紫外-可见吸收光谱(UV-Vis)、共振瑞利散射(RRS)光谱等技术对合成的类普鲁士蓝纳米进行了表征,并将其应用于修饰电极的制备。本文的主要研究内容及成果如下：1.聚二烯丙基二甲基氯化铵和壳聚糖保护的普鲁士蓝／金纳米/4-巯基苯硼酸自组装修饰玻碳电极对单糖分子的电化学识别研究了一种新的用于测定单糖分子的电流型传感器。本实验中首先将聚二烯丙基二甲基氯化铵(PDDA)和壳聚糖(CS)作为保护剂合成的普鲁士蓝纳米修饰在玻碳电极表面,然后利用自组装技术,将金纳米组装在修饰有普鲁士蓝的电极表面,最后利用金和巯基之间强的成键能力,将4-巯基苯硼酸(MPBA)连接到电极上,制作完成了新的传感器。实验中利用透射电子显微镜和紫外-可见分光光度计对新合成的普鲁士蓝纳米进行了表征,同时利用循环伏安和交流阻抗技术对新制备的修饰电极进行了表征。除此之外,测定了修饰电极与单糖分子结合前后的表面pKa值,并对修饰电极响应单糖分子的最佳酸度值进行了计算。实验表明,该修饰电极在Fe(CN)63-/4-为电化学探针时,对葡萄糖、甘露糖和果糖有较好的电化学响应,建立了一种准确测定单糖分子的新方法。2.多层组装结构的电流型传感器用于对单糖分子的测定采用滴膜的方法首先将聚二烯丙基二甲基氯化铵和壳聚糖为保护剂合成的纳米普鲁士蓝固定在玻碳电极表面,此时电极表面带有大量正电荷并存在大量的氨基；然后利用静电吸附及金纳米与氨基之间的相互作用,将金纳米组装在普鲁士蓝修饰电极的表面；接着将巯基乙胺组装在金纳米表面；最后根据氨基与醛基可以形成希夫碱的反应,依次将戊二醛和3-氨基苯硼酸组装在修饰有巯基乙胺的电极表面,得到了PDDA和CS保护的普鲁十蓝／金纳米／巯基乙胺／3-氨基苯硼酸修饰玻碳电极。利用循环伏安和交流阻抗技术对该修饰电极的电化学行为进行了表征,同时对该修饰电极与单糖分子结合前后的表面pΚa值进行了测定,准确计算了该修饰电极响应不同单糖分子时的最佳pH值。实验表明,在含有Fe(CN)63-/4-探针的溶液中,该修饰电极对半乳糖、甘露糖和果糖有很好的电化学响应,并且峰电流的变化与单糖浓度的变化存在较好的线性关系,所以该法有望成为测定单糖分子的一种新方法。3.铈掺杂纳米普鲁士蓝的研究及其对过氧化氢的响应采用聚二烯丙基二甲基氯化铵和壳聚糖两种有机高聚物作为保护剂,用金属铈离子代替普鲁士蓝中的部分铁离子,首次合成了铈离子掺杂的类普鲁十蓝纳米溶胶。利用透射电子显微镜、紫外光谱仪和荧光光谱仪对该类普鲁士蓝纳米颗粒的大小、形状、吸收峰以及散射峰的位置和强度进行了表征。之后将该纳米溶胶滴涂在玻碳电极表面,制备了类普鲁士蓝纳米修饰的电极,并利用循环伏安和差分脉冲技术对该电极的电化学行为进行了表征。研究发现该修饰电极对过氧化氢分子有较好的催化还原作用,且在过氧化氢浓度为5.0×10-5～1.4×10-2M范围内,还原峰电流与浓度之间存在较好的线性关系,因此建立了一种定量测定过氧化氢的新方法。更多还原

【Abstract】 Prussian blue (PB) is an inorganic polycrystal and has been widely used as an electron transfer mediator in the amperometric biosensors since its deposition on the surface of electrodes in 1978. However, the traditional PB modified electrodes are not stable in neutral and alkaline pH and the PB films resolve easily, which greatly limit their application. To solve this problem, a large number of PB nanoparticles have been synthesized with the stabilizers, such as PVP, PSS, PVA, and so on. These protective polymers could not only improve the stability of PB modified electrode in alkaline solutions, but also bring attractive properties to the nanoparticles. In addition, the cubic PB structure is not limited to the iron ion and combinations of several transition metal ions in different oxidation states such as Co, Ni, Cu, etc.. In this paper, FeCl3 and K4[Fe(CN)6] were used to synthesize PB nanoparticles protected by chitosan (CS) and poly(diallyldimethylammonium chloride) (PDDA). Furthermore, PB analogue nanoparticles also protected by both CS and PDDA were synthesized using Ce(NO3)3 and K4[Fe(CN)6]. Transmission electron microscopy (TEM), UV-Vis absorption spectroscopy and resonance Rayleigh scattering (RRS) technique were employed to characterize the PB and PB analogue nanoparticles.The main content and some conclusions of the thesis are as follows:1. Electrochemical recognition for sugars on the chitosan-poly(diallyldimethylammonium chloride)-Prussian blue /nano-Au/4-mercaptophenylboronic acid modified glassy carbon electrodeA new amperometric biosensor for the detection of sugars was prepared. A glassy carbon electrode was modified with PB nanoparticles protected by CS and PDDA and then gold nanoparticles were assembled onto the electrode followed by the assembly of 4-mercaptophenylboronic acid (MPBA) onto the surface of gold nanoparticles through a sulfur-Au bond to fabricate a self-assembled biosensor. The PB nanoparticles protected by CS and PDDA were characterized using TEM and UV-vis absorption spectroscopy. The characterization of the self-assembled electrode was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The pKa values of the MPBA monolayer before and after combining with sugars were determined. The fabricated electrode exhibited excellent performances for determining D(+)-glucose, D(+)-mannose and D(-)-fructose on the basis of the change in ip of the Fe(CN)63-/4- ion in the presence of sugars.2. Multilayer structured amperometric biosensor based on the self-assembling technique for recognition of sugarsPB nanoparticles protected by CS and PDDA were cast onto a glassy carbon electrode surface directly. And gold nanoparticles were then assembled onto the electrode through strong binding interaction between gold nanoparticles and amino groups of CS and electrostatic interaction between oppositely charged gold nanoparticles and PDDA. Following this, cysteamine hydrochloride (Cys) was assembled onto the gold nanoparticles through a sulfur-Au bond, further reacted with glutaraldehyde (Glu) via Schiff s base formation. Finally,3-aminophenylboronic acid (APBA) was immobilized to the surface of upper modified electrode. TEM was employed to characterize CS and PDDA protected PB nanoparticles (CS-PDDA-nano-PB). The properties of the modified electrode were characterized by CV and EIS. The pKa values of the APBA monolayer before and after combining with sugars were determined. The fabricated electrode exhibited excellent performances for determining D(+)-galactose, D(+)-mannose and D(-)-fructose on the basis of the change in ip of the Fe(CN)63-/4-ion in the presence of sugars. Based on this, a new biosensor for determining sugars has been developed.3. A new material based on nanostructured Prussian blue analogue film doped with Ce(III) for development of hydrogen peroxide sensorPB analogue nanoparticles doped with Ce3+, have been synthesized using CS and PDDA as protective matrix, which were cast onto a glassy carbon electrode surface directly. TEM, UV-vis absorption spectroscopy and resonance Rayleigh scattering (RRS) technique were employed to characterize CS and PDDA protected PB analogue nanoparticles. And the properties of this modified electrode were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Compared with the bare glassy carbon electrode, the modified electrode exhibited excellent performances for determining H2O2 And the electrochemical behavior of H2O2 at the modified electrode was investigated by CV and differential pulse voltammetry (DPV). A good linearity was obtained in the concentration range of 5.0×10-5～1.4～10-2M with a detection limit of 8.21 x 10-6M under the optimum conditions.更多还原