【作者】 吴敏；

【导师】 王清江； 何品刚； 方禹之；

【作者基本信息】 华东师范大学 ， 分析化学， 2014， 博士

【摘要】 随着工业的快速发展,在全球范围内都不同程度地出现了环境污染问题,如大气污染、海洋污染、城市环境问题等。就我国的国情而言,主要的环境问题有以下几个方面：一是以大气颗粒物为主的城市空气污染,二是以有机物和重金属污染为主的水质污染,三是工业有毒的废弃物和生活垃圾对水、大气和土地的污染。要解决上述环境问题,对各种污染物进行分析和检测显然是必不可少的。因此,对污染物进行灵敏的检测引起了世界各国的普遍关注,也越来越为我国环保部门所重视。电化学分析方法具有操作简便、价格便宜、灵敏、快速、绿色环保以及易于微型化等优点,极大地引起了人们的兴趣并被广泛地应用于环境污染物的检测,如水质监测、药物分析和环境监测等方面。本论文基于电化学分析技术高效、快速、灵敏、方便的优势,建立新的实验体系对苏丹红Ⅰ、苯酚、亚硫酸根、亚硝酸根、重金属离子等物质进行检测,并且实际检测了水、食品、中草药等,具体研究内容如下：1.多壁碳纳米管/壳聚糖复合材料修饰玻碳电极的研制及苏丹红Ⅰ的检测研制了多壁碳纳米管／壳聚糖复合材料修饰玻碳电极用于苏丹红Ⅰ的电化学检测。利用多壁碳纳米管和壳聚糖修饰玻碳电极,用循环伏安法和差分脉冲伏安法检测苏丹红Ⅰ；对实验条件进行了优化,如pH值、扫描速率、壳聚糖与多壁碳纳米管的质量比；在最佳的实验条件下,采用差分脉冲伏安法确定其线性范围,检出限达到10-8mol/L数量级。将其用于辣椒中苏丹红Ⅰ的含量的测定,得到了令人满意的结果。2.石墨烯/多壁碳纳米管/BMIMPF6纳米复合材料修饰电极的研制及对苯二酚和邻苯二酚的同时检测研制了GR/MWCNTs/BMIMPF6/GCE修饰电极用于同时测定对苯二酚和邻苯二酚。在该电极中一维的多壁碳纳米管和二维的石墨烯共同构成了一个三维的结构,不仅增强了石墨烯复合材料的利用率,BMIMPF6的加入也提高了电极的分散性和稳定性,从而实现了对苯二酚和邻苯二酚的同时测定。数据分析显示,该修饰电极降低了氧化过电位并显著地提高了峰值电流,表现出对HQ和CT具有高的电催化活性。修饰电极GR/MWCNTs/BMIMPF6/GCE检出限低, HQ和CT的检出限分别为0.1μM和0.06μM。该方法可以用于进一步开发其他酚类化合物的电化学传感器。3.石墨烯-壳聚糖/金纳米粒子修饰电极的研制及亚硫酸根和亚硝酸根离子的同时检测研制了GR-CS/AuNPs GCE电化学传感器用于同时测定SO32-和NO2。采用透射电子显微镜(TEM)分别对GR和GR-CS/AuNPs GCE进行了表征。用循环伏安法研究了S032-和N02-在GR-CS/AuNPs GCE上的电化学行为。结果表明,该修饰电极对S032-和N02-有较好的电催化活性,并能实现对两种离子的同时测定,S032-和NO2-在该修饰电极上的线性范围分别为5μmol/L-0.41mmol/L、1μmol/L-0.38mmol/L,检出限分别为1μmol/L、0.25μmol/L(S/N=3).GR-CS/AuNPsGCE具有很好的稳定性、重现性和灵敏度。该电极用于实际水样的SO32-和NO2-的含量测定,回收率为97.2-102.6%。4.石墨烯/铋复合材料修饰玻碳电极的研制及中草药中铅和镉的同时检测研制了石墨烯/铋复合材料修饰玻碳电极‘并运用于中草药中铅和镉的同时检测。首先采用滴涂法得到石墨烯(GR)修饰的玻碳电极(GCE),再采用电沉积的方法制得GR/Bi GCE修饰电极。用方波溶出伏安法研究了Cd2+和Pb2+在GR/Bi GCE上的电化学行为。结果表明,此修饰电极对Cd2+和Pb2+均有较好的电催化活性作用,并且能实现对两种离子的同时测定。Cd2+和Pb2+在该修饰电极上的线性范围分别均为0.01-85μM,检出限均为0.01μM。GR/Bi GCE具有很好的稳定性、重现性和灵敏度。此电极用于中草药中Cd2+和Pb2+的含量测定,结果令人满意。5.钯纳米粒子/石墨烯/壳聚糖修饰电极的研制及抗坏血酸、多巴胺和尿酸的同时检测制备了钯纳米粒子/石墨烯/壳聚糖修饰电极(PdNPs/GR/CS GCE),并用于抗坏血酸、多巴胺和尿酸的同时检测。相对于裸玻碳电极、钯纳米粒子修饰电极、石墨烯/壳聚糖修饰电极,该电极在循环伏安法和微分脉冲伏安法中,对抗坏血酸、多巴胺、尿酸表现出更好的电化学催化活性。微分脉冲伏安法用于同时检测混合物中的抗坏血酸、多巴胺和尿酸,三者的峰电位分别为252mv,144mv和396mv。抗坏血酸、多巴胺和尿酸的检测下限分别为20gm,0.1μm和0.17μm。这一钯纳米粒子/石墨烯/壳聚糖修饰电极在稳定性、灵敏度、设备简单性和经济方面都表现出许多优点。更多还原

【Abstract】 Currently, environmental pollution problems such as air pollution, marine pollution, and urban environmental issues are more and more serious around the world. Electrochemical analysis method with the advantages of simple, cheap, sensitive, rapid and easy-to-green miniaturization, etc., it is widely used in the detection of environmental pollutants, such as water quality monitoring, drug analysis and environmental monitoring.In this paper, we mainly focused on the development establishment of new electrochemical sensors for detecting Sudan Ⅰ, phenol, sulfite, nitrite, heavy metals and other substances based on efficient, rapid, sensitive and convenient advantages of nano-metarials modified electrodes. These proposed methods were employed to real samples and the experimental results were satisfied. The detailed profile in this dissertation is shown as follows.1. Electrochemical detection of Sudan Ⅰ using a multi-walled carbon nanotube/chitosan composite modified glassy carbon electrodeA simple and sensitive electrochemical method was developed to determine Sudan Ⅰ by cyclic voltammetry and differential pulse voltammetry using a glassy carbon electrode modified with a chitosan/carbon nanotube composite. In cyclic voltammetry, Sudan Ⅰ exhibited a well-defined oxidation peak located at0.72V at the multi-walled carbon nanotube (MWCNT)/chitosan-modified GCE. The determination conditions, including pH, scan rate, and chitosan:MWCNT mass ratio at the modified electrode, were optimized. Under the optimum experimental conditions, Sudan Ⅰ could be linearly detected by differential pulse voltammetry with a detection limit of3.0×10-8mol/L.2. Simultaneous electrochemical determination of hydroquinone and catechol based on three-dimensional Graphene/MWCNTs/BMIMPF6nanocomposite modified electrodeA three-dimensional (3-D) carbon electrode was fabricated in the form of1-D multiwalled carbon nanotubes (MWCNTs) and2-D graphene (GR), using ionic liquid 1-butyl-3-methylimidazolium (BMIMPF6) to improve the dispersibility and stability of the3-D carbon electrode. This GR/MWCNTs/BMIMPF6modified glassy carbon electrode (GCE) was a highly sensitive electrochemical sensor for the simultaneous determination of hydroquinone (1,4-dihydroxybenzene, HQ) and catechol (1,2-dihydroxybenzene, CT). The GR were characterised using a transmission electron microscope (TEM). The electrochemical behaviours of HQ and CT at the GR/MWCNTs/BMIMPF6/GCE were investigated using cyclic voltammetry (CV) and differential pulse voltammetry. The chemically modified electrode displayed excellent electrochemical catalytic activities towards HQ and CT. Linear relationships between the values of the oxidation peak current and the concentration of HQ and CT were obtained in the ranges of0.5μmol/L to2.9mmol/L and0.2μmol/L to0.66mmol/L with detection limits (S/N=3) of0.1μmol/L and0.06μmol/L, respectively. This GR/MWCNTs/BMIMPF6/GCE showed many advantages in terms of stability, sensitivity, facility and economy.3. Simultaneous electrochemical determination of sulfite and nitrite using a gold nanoparticle/graphene-chitosan modified electrodeA highly sensitive electrochemical sensor for the simultaneous determination of SO32-and NO2-based on a glassy carbon electrode(GCE) modified with graphene(GR)-chitosan(CS) and gold nanoparticles(AuNPs) has been developed. The GR and GR-CS/AuNPs GCEs were characterised using a transmission electron microscope (TEM). The electrochemical behaviours of SO32-and NO2-at the GR-CS/AuNPs GCE were investigated using cyclic voltammetry (CV). The chemically modified electrode displayed excellent electrochemical catalytic activities towards sulphite and nitrite. Linear relationships between the values of the oxidation peak current and the concentration of SO32-and NO2-were obtained in the ranges of5μmol/L to0.41mmol/L(R=0.9986) and1μmol/L to0.38mmol/L(R=0.9940) with detection limits(S/N=3) of1μmol/L and0.25μmol/L, respectively. This GR-CS/AuNPs GCE showed many advantages in terms of stability, sensitivity, facility and economy. The proposed method was employed to example real samples with recoveries of97.2to102.6%. 4. Electrochemical detection of Cd2+and Pb2+in Chinese herbals using graphene/Bi composites modified glassy carbon electrodeThe GR/Bi GCE modified electrode was prepared by drop-coating graphene (GR) on the glassy carbon electrode and electrodeposition of Bi on the surface of GR. The electrochemical behaviors of Cd2+and Pb2+were studied on GR/Bi GCE with square wave stripping voltammetry. The results showed that this modified electrode had good electro-catalytic activity to Cd2+and Pb2+, and their linear ranges at the modified electrode were both from0.01to85μM with low detection limits of0.01μM. This GR/Bi GCE was of good stability, reproducibility and sensitivity. It was used for the simultaneous determination of Cd2+and Pb2+in medicine and the results were satisfied.5. Simultaneous electrochemical determination of Ascorbic Acid, Dopamine and Uric Acid using a palladium nanoparticle/Graphene/Chitosan Modified ElectrodeA palladium nanoparticle/graphene/chitosan/glassy carbon electrode (PdNPs/GR/CS GCE) was prepared and characterized. This chemical modified electrode displayed excellent eletrochemical catalytic activities towards ascorbic acid (AA), dopamine (DA) and uric acid (UA) compared with bare GCE, PdNPs/GCE and GR/CS GCE by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). All oxidation potentials of AA, DA and UA at the PdNPs/GR/CS GCE shifted negatively and the peak currents were much larger than other electrodes. DPV was used for simultaneous determination of AA, DA and UA in their mixture, and the peak potential separations between AA and DA, DA and UA, AA and UA were252mV,144mV and396mV, respectively. The limits of detection (S/N=3) for AA, DA and UA were20μM,0.1μM and0.17μM, respectively. This PdNPs/GR/CS GCE showed many merits in stability, sensitivity, facility and economy.更多还原