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超分子自组装膜修饰电极的制备及电化学应用
Preparation and Electrochemical Application of Supermolecule Self-assembled Modified Electrode
【作者】 郑玉欣;
【导师】 周长利;
【作者基本信息】 济南大学 , 应用化学, 2009, 硕士
【摘要】 本文自行合成了超分子化合物单-6-对甲基苯磺酰-β-环糊精(6-OTS-β-CD),并在此基础上继续合成了功能化离子液体β-环糊精季铵化的吡啶类离子液体[CDbPy]BF4,以它们为修饰剂,首次制备了超分子自组装膜化学修饰电极,并进行了电化学表征,结果表明功能化离子液体超分子自组装膜修饰电极的灵敏度最好。研究了肾上腺素、抗坏血酸和1-亚硝基-2-萘酚、硝基氯苯等生物活性物质和环境污染物在修饰电极上的电化学行为,并进行了应用研究,建立了相关分析方法。本论文的研究工作共分为四部分,其主要内容如下:第一部分合成超分子化合物6-OTs-β-CD,把它修饰在电极上制备了超分子自组装膜修饰电极6-OTS-β-CD/L-cys/Au,铁氰化钾为电化学探针,用循环伏安法和交流阻抗法对电极进行了电化学表征,在此修饰电极上首次对1-亚硝基-2-萘酚的电化学特性进行了研究。在0.1 mol/L PBS (pH=5.04)底液中,1-亚硝基-2-萘酚在+0.582 V和+0.482 V (vs .SCE)处产生灵敏的准可逆氧化还原峰,电极反应受扩散控制。1-亚硝基-2-萘酚的氧化峰电流与其浓度在1.0×10-6~1.0×10-4 mol/L范围内呈良好的线性关系,检测下限可达3.33×10-7 mol/L,同一支电极连续九次测定5.0×10-5 mol/L的1-亚硝基-2-萘酚溶液,相对标准偏差为1.66%,说明电极的稳定性和重现性很好。第二部分制备了新型修饰电极6-OTS-β-CD/PDDA/Au,用同样的方法对电极进行了电化学表征,利用循环伏安法,示差脉冲伏安法等电化学方法研究了肾上腺素的电化学特性。在0.1mol/L PBS (pH=7.4)底液中,肾上腺素在+ 0.354V(vs.SCE)处产生一个灵敏的不可逆氧化峰,电极反应受扩散控制。该法用于盐酸肾上腺素针剂中肾上腺素含量的测定,结果令人满意。第三部分合成了功能化的离子液体[CDbPy]BF4,首次把它修饰在不同基体电极上,制备了三种不同类型的功能化离子液体超分子自组装膜修饰电极。以二茂铁为电化学探针,考察了双层膜数的影响,并对电极进行了循环伏安,交流阻抗和计时电量表征,计算得到了修饰电极的真实面积。考察了扫描速度对二茂铁氧化还原峰电流影响,结果表明,电极反应主要受扩散控制。通过对修饰电极各种参数的比较,确定([CDIL]/L-cys)2/Au的电极性能最好。第四部分利用不同的功能化离子液体超分子自组装膜修饰电极,分别研究了抗坏血酸和硝基氯苯的电化学行为。优化了测定条件,考察了扫描速度的影响,结果表明,电极反应过程主要受扩散控制。该法用于Vc片剂中抗坏血酸含量的测定,得到了令人满意的结果。通过邻、间、对三种硝基氯苯各种实验参数的比较,结果表明,修饰电极对对硝基氯苯的选择性电催化作用最好,因此以它为研究对象进行了实际的样品测定,结果满意。
【Abstract】 In this thesis, supermolecule self-assemble modified electrodes were fabricated by using self-synthetical supermolecule compound such as 6-OTs-β-CD and functional ionic liquid of pyridinium derivative of quaternary ammonium salt ofβ-cyclodextrin ([CDbPy]BF4) to study the electrochemical behavior of bioactive materials and contamination of environment such as epinephrine, ascorbic acid, 1-nitrosol-2-naphthol and chloronitrobenzene (CNB). Additional sensitivity and selectivity can be provided by utilizing specifically character and moleculed structure of modifiers to study electrocatalyze and analytical determination. The work of this thesis was divided into four parts:In the first part, supermolecule compound 6-OTs-β-CD was synthesized and used it as modifier to fabricate modified electrode 6-OTs-β-CD/L-cys/Au. With potassium ferricyanide as electrochemical probe, charactered the modified electrode by CV and EIS and investigated the electrochemical speciality of 1-nitroso-2- naphthol by CV at the first time. Sensitive semi-reversible redox peaks were observed at +0.582 V and -0.482 V (vs .SCE)in 0.1mol/L pH 5.04 phosphate buffer solution. The experimental results showed that the charge transfer process in the modified electrode was controlled by diffusion. The anodic current increased linearly with the concentration of 1-nitroso-2- naphthol in the range of 1.0×10-6 ~ 1.0×10-4 mol/L. The determination limit was 3.33×10-7 mol/L. The relative standard deviation of 1.66% was obtained by nine successive determination of 5.0×10-5 mol/L 1-nitroso-2- naphthol.In the second part, modified electrode 6-OTs-β-CD/PDDA/Au was fabricated, charactered it by CV and EIS with potassium ferricyanide as electrochemical probe, and investigated the electrochemical speciality of epinephrine by CV and DPV. A sensitive irreversible oxidation peak was observed at +0.354V( vs .SCE)in 0.1mol/L pH 7.4 phosphate buffer solution. The experimental results showed that the charge transfer process in the modified electrode was controlled by diffusion. This modified electrode had been used satisfactorily in the determination of epinephrine content in injection.In the third part, functional ionic liquid ([CDbPy]BF4) was synthesized and used it as modifier to fabricate three type self-assembled modified electrode on the different electrode at the first time. With ferrocene as electrochemical probe, investigated the effect of different bilayer films and charactered these modified electrodes by CV, EIS and Chronocoulometry. Moreover, the real area of the modified graphite electrode was obtained by calculating. The influence of scan rate to ferrocene was investigated and the experimental results showed that the charge transfer process in the modified electrode was controlled by diffusion. Propertie of ([CDIL]/L-cys)2/Au was the best than the others by comparing the parameters of all modified electrodes.In the forth part, different functionalized ionic liquid modified electrodes were used for researching the electrochemical behaviors of ascorbic acid and chloronitrobenzen, respectively. The effect of scan rate was investigated in the optimized condition, and the experimental results showed that the charge transfer process in the modified electrode was controlled by diffusion. This modified electrode has been used satisfactorily in the determination of ascorbic acid content in Vc tablet. The result showed that modified electrode possessed the better electrocatalysed effect on the deoxidization of p-CNB than o- CNB and m- CNB, wherefore, p-CNB was used was used as the sample of measurement in this paper with satisfactory result.
【Key words】 Supermolecule compound; Self-assembled; Chemical modified electrode; 1-nitroso-2- naphthol; Epinephrine; Ascorbic acid; Chloronitrobenzen;