【作者】 李冰心；

【导师】 徐岚；

【作者基本信息】 西南大学 ， 分析化学， 2011， 硕士

【摘要】 电化学传感器的研制已成为电分析化学研究领域中一个非常重要的课题,它们具有响应快、选择性较好、设备简单、操作简易、成本低廉和高灵敏性等众多优点,已广泛应用于食品分析、生物医药检测、环境监测等领域。本文主要研制了用于手性扁桃酸识别以及甲醛检测的电化学传感器。手性Salen及其配合物的设计和合成是研制高选择性电化学传感器的关键,本文合成了手性Salen-Cu(Ⅱ)、Salen-Co(Ⅲ)和Salen-Co(Ⅱ)配合物,并将其应用到电化学传感器中,讨论了传感器的构成、性能、选择性以及响应机理。主要有以下三个方面的工作：1.以3,5-二叔丁基水杨醛和(1R,2R)-环己二胺为原料,合成了手性(R,R)-N,N’-二(3,5-二叔丁基水杨醛)-1,2-环己二胺铜配合物[Salen-Cu(Ⅱ)],以该金属配合物作为载体制作对映异构PVC膜选择性电极(Salen-Cu/PVC)。由于手性Salen-Cu(Ⅱ)与手性扁桃酸(R-MA和S-MA)形成配合物的稳定性不同,电极能优先响应R-MA,线性范围为1.0×10-4～1.0×10-1mol/L,斜率为-52.1 mV/dec,检测限为6.0×10-mol/L,其对映异构选择性系数logK(?)为-2.17。2.合成了手性(R,R)-N,N’-二(3,5-二叔丁基水杨醛)-1,2-环己二胺钴配合物[Salen-Co(III)]作为PVC膜电极的载体。在优化条件下,将载体、增塑剂和PVC粉按一定比例制作PVC膜选择性电极(Salen-Co/PVC)。由于手性Salen-Co(Ⅲ)与手性扁桃酸(R-MA或S-MA)配位形成络合物的稳定性不同,电极能优先响应R-MA,对映异构选择性系数logKR,SPot为-2.36,线性范围为1.0×10-4～1.0×10-1mol/L,斜率为-55.7 mV/dec,检测限为2.0×10-5mol/L。3.以3,5-二叔丁基水杨醛和(1R,2R)-环己二胺为原料,合成了(R,R)-N,N’-二(3,5-二叔丁基水杨醛)-1,2环己二胺钴配合物[Salen-Co(Ⅱ)],以此作为化学修饰剂,利用直接混合法将化学修饰剂、液体石蜡和石墨粉按一定比例混合制作成修饰碳糊电极(Salen-Co/CPE)。实验表明,该电极对甲醛具有良好的电催化作用,氧化峰电流与甲醛的浓度在3.0x10-21.2x10-1mol/L的范围内具有良好的线性关系,检出限为3.33×10-3mol/L。更多还原

【Abstract】 The study of electrochemical sensors has become a very important topic in analytical chemistry, which has been widely used in food analysis, biomedical detection, environmental monitoring and other fields due to its fast response, good selectivity, simple equipment and operation, low cost and high sensitivity, etc. In this paper, the electrochemical sensors were applied in recognition of chiral mandelic acid and detection for formaldehyde. To design and synthesize chiral Salen and its metal complexes are very vital for the developed electrochemical sensors with good selectivity, chiral Salen-Cu(II), Salen-Co(III) and Salen-Co(II) complexes have been synthesized and the electrochemical sensors were fabricated by using these compounds as recognition elements. Meanwhile, the sensor constitution, performance, selectivity and response mechanism were investigated. The main contents are as following:1. Chiral (R,R)-N,N’-bis(3,5-di-tert-butylsalicylaldehyde)-1,2-diaminocyclohexane copper complex [Salen-Cu(II)] was synthesized by 3,5-di-tert-butylsalicylaldehyde and (1R,2R)-diaminocyclo-hexane, which was prepared as the carrier of enantioseletive PVC membrane electrode (Salen-Cu /PVC). Due to the different stabilities of ligand complexes, which were formed by Salen-Cu(II) compound coordinating with chiral enantiomeric mandelic acid(R-MA or S-MA), the electrode can preferentially respond to R-mandelic acid, exhibiting near Nernstian response of-52.1 mV/dec in the concentration range from 1.0×10-4 to 1.0×10-1mol/L with a detection limit of 6.0×10-5mol/L and the enantioselectivity coefficient logKR,SPot,-2.17.2. Chiral (R,R)-N,N’-bis(3,5-di-tert-butyl salicylaldehyde)-1,2-diaminocyclohexane cobalt complex [Salen-Co(III)] was employed as the chiral selector of PVC membrane electrode, which was synthesized via 3,5-di-tert-butyl salicylaldehyde and (1R,2R)-diaminocyclohexane. Under the optimized conditions, the selective PVC membrane electrode was prepared by uniformly mixing the carrier, plasticizer and PVC powder in a certain percentage (Salen-Co/PVC). Attributed to the different stabilities of ligand complexes that was formed by coordinated bond between Salen-Co(Ⅲ) compound and chiral enantiomeric mandelic acid(R-MA or S-MA), the electrode displayes near Nernstian slope of -55.7 mV/dec in a linear range of 1.0×10-4 to 1.0×10-1 mol/L for R-mandelic acid with a detection limit of 2.0×10-5 mol/L and an enantioselectivity coefficient logKR,SPot,-2.36.3. Chiral (R,R)-N,N’-bis(3,5-di-tert-butyl salicylaldehyde)-1,2-diaminocyclohexane cobalt complex [Salen-Co(II)] has been used as a chemical modifier, which was synthesized via 3,5-di-tert-butyl salicylaldehyde and (1R,2R)-diaminocyclohexane. Salen-Co(II) modified carbon paste electrode (Salen-Co/CPE) have been fabricated by directly mixing of chemical modifiers, paraffin oil and graphite powder in proportion. The devoleped electrode exhibits a good electrocatalytic activity for formaldehyde by chronoamperometry and a linear range from 3.0×10-2 to 1.2×10-1mol/L with the detection limit of 3.33×10-3mol/L were obtained.更多还原