【作者】 申丽华；

【导师】 张成孝；

【作者基本信息】 陕西师范大学 ， 分析化学， 2007， 博士

【摘要】 现代能源科学、环境科学、生命科学和材料科学的日益发展,对分析化学提出了越来越高的要求,与各个学科的交叉和相互渗透促进了分析化学的发展,也给分析化学的发展带来新的机遇。纳米材料因具有特有的量子尺寸效应和表面效应,在发光材料、光敏传感器等方面具有广阔的应用前景,可望在生物识别检测中成为一类新型的生物标记物和传感材料。将纳米材料引入分析化学研究中成为分析化学的一个研究方向。电化学发光(Electrogenenrated chemiluminescence, ECL)是在电极上施加一定的电压进行电化学反应,电极反应产物之间或电极反应产物与溶液中某组分进行化学反应而产生的一种光辐射。基于电化学发光强度与待测物质的定量关系而建立的分析方法称为电化学发光分析法。电化学发光分析法已经成功地应用在环境科学、生命科学和材料科学等领域。发现新的电化学发光体系,建立简单、灵敏、快速的电化学发光分析方法和构建简单、稳定性良好、廉价的电化学发光检测器一直是电化学发光研究的基础工作。用电化学发光手段研究纳米粒子的光电行为也已起步,并给电化学发光分析带来新的机遇和挑战。本论文旨在研究半导体纳米粒子的光电特性,探讨其发光机理,更好地理解半导体纳米粒子在电化学发光过程中的电子转移理论,为半导体纳米粒子在电化学发光分析和光电转换器件的应用提供参考和理论指导：构建简单、廉价的电化学发光检测器,提高其稳定性；发现新的电化学发光体系,建立简单、灵敏、快速的电化学发光分析方法。主要研究ZnS、ZnO、TiO2内米粒子的电化学发光行为。利用高分子交联聚合法固定化钌联吡啶,建立碳糊电极上测定山莨菪碱的新方法；研究电化学发光体系阿莫西林-表面活性剂-过氧化氢的电化学发光现象,探讨其发光机理,建立电化学发光法测定阿莫西林的新方法。并利用化学发光分析法建立简单、快速、灵敏的药物维生素B4、利福平、阿莫西林的分析方法。第一章为引言,该部分系统的介绍了电化学发光分析法的基本原理和常见的电化学发光体系,总结了Ru(by)32+固相电化学发光的固定化方法,评述了电化学发光分析法的研究进展；简要地介绍了纳米材料的定义、分类、特性和合成方法,重点介绍了半导体纳米材料的光电特性。第二章为半导体纳米粒子的电化学发光行为研究。研究了ZnS纳米粒子在碱性水溶液中的电化学发光行为,提出了可能的电化学发光机理,表明ZnS纳米粒子在碱性介质中形成的壳核结构在电化学发光过程中起着重要作用；研究了ZnO纳米粒子在碱性介质中的电化学和电化学发光行为,发现ZnO纳米粒子的表面钝化作用影响ZnO纳米粒子的电化学过程；研究了TiO2纳米粒子在碱性水溶液中的电化学发光行为,探讨了可能的发光机理。第三章为药物电化学发光分析方法研究。主要做了两个工作,其一,高分子交联聚合法固定化钌联吡啶测定山莨菪碱。在电化学发光分析中应用最多电化学发光体系是Ru(bpy)32+电化学发光体系,但在流动体系的电化学发光检测中,必须不断地注入昂贵的Ru(bpy)32+到反应体系中而被大量消耗。由于Ru(bpy)32+在电极上可循环利用,可将Ru(bpy)32+固定化制作检测器。为此,我们利用高分子交联聚合法固定化钌联吡啶,构建简单、廉价、稳定性好的钌联吡啶固定化方法,建立测定药物山莨菪碱的电化学发光新方法。以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂合成了包埋有Ru(bpy)2(dcbpy)2+的高分子聚合物,将Ru(bpy)2(dcbpy)2+固定于碳糊电极上,建立了一种新的固定化钌联吡啶的方法。以三丙胺为对象,考察了Ru(bpy)2(dcbpy)2+固定化碳糊电极的稳定性和电化学活性；基于山莨菪碱对Ru(bpy)2(dcbpy)2+电化学发光的增强作用,建立了电化学发光法测定山莨菪碱的新方法。其二,电化学发光法测定阿莫西林。电化学发光法作为一种高灵敏度的分析方法也己被广泛的应用于药物分析。电化学发光分析法对药物的检测一般都是鲁米诺或钉联毗啶等发光体系。发现新的电化学发光体系,建立简单、灵敏、快速的电化学发光药物分析方法,是电化学发光研究的基础工作。本文旨在利用电化学氧化或者还原某些具有荧光特性的药物,发生氧化还原反应产生电化学发光,探索新的电化学发光体系,建立新的简单、灵敏、快速电化学发光药物分析法,拓宽电化学发光分析的应用范围。以阿莫西林为研究对象,发现在有表面活性剂十六烷基三甲基溴化铵存在时,在+1.5V～-1.0V之间线性扫描,在石墨电极上,在-0.7V的还原电位产生电化学发光,过氧化氢的加入能极大的增强此电化学发光强度。基于此,建立了电化学发光法测定阿莫西林的新方法；探讨了发光机理。第四章为流动注射化学发光法测定药物分析方法的研究。化学发光分析法以其灵敏度高、线性范围宽、分析速度快、仪器简单以及易于实现自动化和连续分析等特点,已被成功的应用于环境、临床医学等领域中。分别建立了测定维生素B4、利福平、阿莫西林的流动注射化学发光分析法。本论文具体研究内容简述如下：1.ZnS纳米粒子在碱性介质中,在-2.0V～(vs.Ag/AgCl, Sat. KCl)+0.86V之间扫描,首次发现了ZnS纳米粒子的带隙电化学发光。通过紫外可见吸收光谱、光致发光光谱、透射电镜以及能谱图证实了ZnS纳米粒子在碱性介质中会形成壳核式结构ZnS/Zn(OH)2提出了ZnS纳米粒子在碱性介质中可能的电化学发光机理。Zn(OH)2对ZnS纳米粒子的表面钝化作用在电化学发光过程中起着重要作用；ZnS纳米粒子在碱性介质中的电化学发光光谱峰～460nm,与ZnS纳米粒子在碱性介质中的观测到的光致发光的光谱峰440nm比较接近,电化学发光光谱和光致发光光谱的接近程度与Zn(OH)2对ZnS纳米粒子的表面钝化程度有关；共反应试剂过硫酸钾能够增强ZnS纳米粒子在碱性介质中的电化学发光。2.以尿素和硝酸锌为原料,采用均匀沉淀法制备了ZnO纳米粒子。利用透射电镜,紫外-可见吸收光谱,光致发光光谱,XRD衍射等对ZnO纳米粒子进行了表征。研究了ZnO纳米粒子在过硫酸钾的碱性溶液中的电化学发光行为,发现其在0V到-2V的循环扫描过程中有很强的发光,并且电化学发光强度与ZnO纳米粒子浓度在1.0×10-5g/mL至1.0×10-3g/mL范围内呈现出良好的线性关系。研究了ZnO纳米粒子修饰碳糊电极在过硫酸钾碱性溶液中的电化学行为,发现ZnO纳米粒子有两对氧化还原峰,碱性介质对ZnO纳米粒子的表面钝化作用影响ZnO纳米粒子的电化学性质。3.以钛酸四正丁脂为原料,采用溶胶-凝胶法,制备了TiO2纳米粒子。利用透射电镜,紫外-可见吸收光谱,X衍射对TiO2纳米进行了表征。重点研究了经酸处理的TiO2纳米粒子在过硫酸钾碱性溶液中的电化学发光行为,发现其在0V到-2V之间循环扫描过程中有很强的电化学发光现象,且电化学发光强度与TiO2纳米粒子浓度在2.0×10-5g/mL～4.0×10-4g/mL范围内呈现出良好的线性关系。4.采用高分子聚合法,以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂合成了包埋有Ru(bpy)2(dcbpy)2+的高分子聚合物。将Ru(bpy)2(dcbpy)2+固定于碳糊电极上,制作了电化学发光检测器。以三丙胺为研究对象考察了该检测器的电化学和电化学发光特性,结果表明该检测器保持了Ru(bpy)2(dcbpy)2+的电化学和电化学发光活性,展现了很好的稳定性,测定TPA的线性范围是2.0×10-6～3.8×10-3M,检出限为6×10-7M(S/N=3)。基于山莨菪碱能增强Ru(bpy)2(dcbpy)2+的ECL强度,建立了电化学发光法测定山莨菪碱的新方法。电化学发光强度与山莨菪碱在3.3×10-6g/mL～1.8×10-4g/mL浓度范围内呈良好的线性关系,检出限为2×10-6g/mL,对2×10-6g/mL的山莨菪碱平行测定35次的相对标准偏差为3.8%,并应用于针剂和片剂中山莨菪碱的测定。5.研究发现,有表面活性剂十六烷基三甲基溴化铵存在时,在+1.5V～-1.0V之间线性扫描,在石墨电极上,阿莫西林能在-0.7V的还原处能产生电化学发光。过氧化氢的加入能极大的增强此电化学发光强度。基于此,建立了电化学发光法测定阿莫西林的新方法；探讨了发光机理。6.在碱性条件下,维生素B4对鲁米诺-过氧化氢体系的化学发光有较强的增敏作用。基于此,结合流动注射技术,建立了测定维生素B4的新方法。在优化的条件下,维生素B4浓度在1.0×10-81.0×10-5g/ml范围内与化学发光强度呈良好的线性关系,检出限为3×10-9g/ml对2.0×10-6g/mL维生素B4平行测定11次,相对标准偏差(RSD)为1.4%。该方法应用于片剂中维生素B4的测定。7.在酸性条件下,高锰酸钾能氧化利福平产生弱化学发光,并且,利福平能极大的增敏亚硫酸钠-高锰酸钾体系的化学发光信号。基于此,结合流动注射技术,建立了测定利福平的新方法。在优化的条件下,利福平浓度在5×10-8g/mL～1.0×10-5g/mL范围内与化学发光强度呈良好的线性关系,检出限为3×10-8g/mL。对2×10-6g/mL的利福平进行11次平行测定,相对标准偏差为2.6%。该法用于胶囊和滴眼液中利福平含量的测定,并初步探讨了该化学发光反应机理。8.在碱性介质中,铁氰化钾能够氧化阿莫西林产生微弱的化学发光,亚硫酸钠对该体系有较强的增敏作用,据此,结合流动注射技术,建立了测定阿莫西林的新方法。阿莫西林浓度在5.0×10-8～2.0×10-5g/mL范围内与化学发光强度呈良好的线性关系,检出限为3～10-8g/mL,对2.0×10-6g/mL的阿莫西林进行11次平行测定,相对标准偏差为1.5%。本法用于胶囊中的阿莫西林的测定,并初步探讨了该化学发光反应机理。本论文对半导体纳米粒子的电化学发光行为的研究及相关基础理论的探索丰富了半导体纳米材料光电性质的研究内容,为半导体纳米粒子在生物电分析和光电转换材料的应用奠定理论基础。利用高分子交联聚合法固定钌联吡啶的方法展现了好的稳定性和好的电化学活性,为钌联吡啶固相电化学发光检测提供了新的思路,建立了电化学发光测定山莨菪碱的新方法。利用电化学直接还原的特性,研究了阿莫西林的电化学发光机理,建立了灵敏、简单、电化学发光直接检测阿莫西林新方法。化学发光分析法检测药物的研究,拓宽了化学发光分析的范围,相关的发光机理丰富了化学发光分析的理论,将促进化学发光分析方法研究的发展。更多还原

【Abstract】 Nanoparticles(NPs) have good applicational prospects in lumine-scence materials and optical sensors due to their unique size-dependent electronic, magnetic, optical, and electrochemical properties. Highly luminescent semiconductor NPs have gained increasing attention for use in light-emitting devices and tagging applications.Electrogenerated chemiluminescence (ECL) is a radioactive charge recombination originating from emitting excited states of electrogenerated species and has been used to investigate the nature of an emitting state, the mechanism by which it is produced, and electron transfer theory. It has also widely been used in pharmaceutical analysis, bioanalysis, enviormental analysis and clinical analysis. The development of a simple, rapid, sensitive and selective method and the fabrication of a simple, cheap and stable analytical detector in ECL analysis have been a long-term goal. Moreover, investigation of ECL of NPs has attracted increasing attentions because NPs have a great potential for developing novel ECL sensors and biological labels for ECL detection.The aim of the present work is to study the ECL behaviors of the semiconductor nanoparticles in aqueous medium and to explore the optical and electrochemical properties of the semiconductor NPs in order to better understand photons, charge-carrier transport, and electron injection phenomena of the semiconductor nanoparticle. Another work in the present thesis aims to develop and investigate a new immobilization approach for fabricating ECL-based detector with long-term stability. A novel ECL detector based on Ru(bpy)2(dcbpy)2+entrapped in a highly cross-linked polymer and mixed with carbon paste was fabricated. A novel ECL analytical method for the determination of raceanisodamine was developed. The ECL phenomena of a system of amoxicillin-surfactant-H2O2was first observed and investigated at graphite electrode at-0.7V during potential scan from+1.5V to-1.0V. The ECL mechanism of the system was discussed and a new ECL method for the determination of amoxicillin was developed. Chemiluminescence analysis is becoming increasing important in various fields owing to its simple instrumentation used, high sensitivity, wide dynamic range, reproducibility, simplicity and rapidity. To explore new CL reaction systems and to develop new chemiluminescence analytical methods is important. In this thesis, the chemiluminescence emission phenomena of the vitamin B4, rifampicin and amoxicillin was investigated respectively, and a new flow injection chemiluminescence analytical method for the determination of the VB4, rifampicin and amoxicillin was developed respectively.The major contents in this thesis are described as follows:In Chapter1, the principle of the ECL and the main ECL systems were introduced. The immobilization methods for Ru(by)32+were summarized and the research progress of the ECL analytical methods was reviewed. Moreover, the definition, classification, properties and synthesis methods of the nanomaterials were briefly introduced and the optical and electrochemistry properties of the semiconductor nanoparticles were mainly described.In Chapter2, the ECL behaviors of semiconductor nanoparticles (NPs) including ZnS, ZnO and TiO2NPs in alkaline solution were investigated.Electrogenerated Chemiluminescence of ZnS Nanoparticles in Alkaline Aqueous Solution A band gap ECL of ZnS NPs in alkaline aqueous solution was first observed at a platinum electrode during the potential applied between-2.0V (vs. Ag/AgCl, Sat. KCl) and+0.86V. The ECL peak of ZnS NPs in0.10M sodium hydroxide solution appeared at+0.86V and the ECL peak wavelength of the ZnS NPs was-460nm. A core/shell of ZnS/Zn(OH)2was demonstrated by a UV-visible absorption(UV absorption) and photoluminescence spectroscopy(PL) spectra, high resolution transmission electron microscopy(HRTEM), and energy dispersive X-ray spectroscopy. The ECL scheme of the ZnS NPs in alkaline aqueous solution was proposed, indicating that the surface passivation effect and the core/shell structure of ZnS/Zn(OH)2played a significant role in the ECL process and that the similarity of the ECL and PL spectra of semiconductor NPs was related with the extent of the surface passivation. The ECL intensity of ZnS NPs in alkaline aqueous solution was greatly enhanced by an addition of K2S2O8. Electrogenerated Chemiluminescence of ZnO Nanoparticles in Alkaline Aqueous Solution with Peroxydisulfate ZnO nanoparticles were prepared by the method of homogeneous precipitation with urea and zinc nitrate. ZnO NPs were characterized by TEM, UV-Vis, PL and X-ray diffraction. A strong ECL emission of ZnO NPs suspended in aqueous solution at a Pt electrode or in nanoparticulate layers modified electrodes including Pt, carbon past and graphite electrode was observed when a potential was applied between0V(vs. Ag/AgCl, Sat. KCl) and-2.0V in0.25M NaOH containing peroxydisulfate. A lineal range between the ECL intensity and the concentration of suspended ZnO NPs in the range from1.0×10-5to1.0×10-3g/mL was obtained. The electrochemical behavior of ZnO NPs was also studied at a ZnO NPs modified carbon paste electrode by entrapping ZnO NPs in carbon paste, which revealed that the electrochemical behavior of ZnO NPs was depended upon the surface passivation effect in a strong alkaline medium.Electrogenerated Chemiluminescence of TiO2Nanoparticles in Alkaline Aqueous Solution TiO2NPs were prepared by the sol-gel method and were characterized by TEM, UV-Vis and XRD. The ECL behavior of TiO2NPs in the alkaline aqueous solution containing K2S2O8was studied. An ECL emission was observed during cyclic potential scan between0V and-2.0V. The ECL intensity had good linear relationship with the concentration of TiO2in the range from2.0×10-5g/mL to4.0×10-4g/mL. Moreover the modified electrode by TiO2NPs was also investigated.In Chapter3, two ECL analytical methods for the determination of pharmaceuticals were developed.Electrogenerated Chemiluminescence of Ruthenium Complex Immobilized in a Highly Cross-linked Polymer and Its Analytical Applications ECL of a ruthenium complex polymer modified carbon paste electrode and its analytical applications were investigated. A ruthenium complex polymer was designed by a highly cross-linked polymer of ruthenium (Ⅱ) bis (2,2’-bipyridine)(2,2’-bipyridyl-4,4’-dicarboxylic acid). The ECL behaviors of ruthenium complex polymer modified carbon paste electrode were investigated in the absence and presence of tripropylamine (TPA). The modified carbon paste electrode exhibited a long-term stability and fine reproducibility. The ECL intensity of the modified electrode was linear with the concentration of TPA in the range from2.0×10-6to3.8×10-3M with a detection limit (S/N=3) of6×10-7M. It was also found that raceanisodamine can enhance the ECL intensity of the modified electrode. The ECL intensity of the modified carbon paste electrode was linear with the concentration of raceanisodamine in the range from3.3×10-6g/mL to1.8×10-4g/mL with a detection limit (S/N=3) of2×10-6M, and the standard deviation for1.0×10-4g/mL in repeated35times measurements is3.8%. This work demonstrates that the entrapment of ruthenium complex in a highly cross-linked polymer is a promising approach to construct an ECL modified electrode which has a long-term stability and fine reproducibility. This work demonstrates that the entrapment of ruthenium complex in a highly cross-linked polymer is a promising approach to construct an ECL modified electrode which has a long-term stability and fine reproducibility and that the ECL modified electrode has a potential application in the ECL detector.Electrogenerated Chemiluminescence Analysis for Amoxicillin It was founded that the amoxicillin produced a weak ECL emission at graphite electrode at-0.7V during potential scan from+1.5V to-1.0V. This weak ECL emission was enhanced greatly by H2O2and CTAB. Based on this finding, a novel sensitive ECL method for the determination of amoxicillin in pharmaceutical preparation was developed. Moreover, the mechanism of the ECL of amoxicillin-CTAB-H2O2was also discussed.In Chapter4. Three flow injection chemiluminescence analytical methods for the determination of vitamin B4, rifampicin and amoxicillin were developed respectively.Determination of VB4with Luminol-H2O2Chemiluminescence System A novel sensitive flow injection chemiluminescence(FI-CL) method for the determination of vitamin B4in pharmaceutical preparation is presented. It is based on the strong enhancement of VB4on the CL between luminol and H2O2in alkaline condition. Various factors affecting the CL emission intensity of the system have been investigated carefully. The enhancement of CL emission intensity is linear with the concentration of vitamin B4in the range from1.0×10-8to1.0×10-5g/mL. The limit of detection is3×10-9g/mL(3a). The relative standard deviation is1.4%for2.0×10-6g/mL vitamin B4in eleven replicate measurements. The proposed method has been successfully applied for the determination of vitamin B4in pharmaceutical preparation of tablets.Flow Injection Chemiluminescence Determination of Rifampicin It was founded that the rifampicin was oxidized by acidic potassium hypermanganate potassium, resulting in generating a weak chemiluminescence emission. Moreover, this weak chemiluminescence emission was greatly enhanced by sodium sulfite. Based on this finding, a novel sensitive FI-CL method for the determination of rifampicin in pharmaceutical preparation is developed. Various factors affecting the CL emission intensity of the system have been investigated. The enhancement of CL emission intensity is linear with the concentration of rifampicin in the range from5×10-8g/mL to1.0×10-5g/mL. The limit of detection is3×10-8g/mL (3σ). The relative standard deviation is2.6%for2.0×10-6g/mL rifampicin in eleven replicate measurements. The proposed method has been successfully applied for the determination of rifampicin in pharmaceutical preparation. Moreover the CL mechanism was also discussed.Flow Injection Chemiluminescence Determination of Amoxicillin It was founded that the amoxicillin was oxidized by potassium ferricyanide in alkaline medium, resulting in generating a weak chemiluminescence emission. The chemiluminescence intensity can be enhanced greatly by sodium sulfite. Based on these findings, a novel sensitive FI-CL method for the determination of amoxicillin in pharmaceutical preparation is developed. Various factors affecting the CL emission intensity of the system have been investigated. The enhancement of CL emission intensity is linear with the concentration of amoxicillin in the range from5.0×10-8to2.0×10-5g/mL. The limit of detection is3×10-8g/mL (3σ). The relative standard deviation is1.5%for2.0×10-6g/mL amoxicillin solution in eleven replicate measurements. The proposed method has been successfully applied for the determination of amoxicillin in pharmaceutical preparation of tablets.更多还原