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纳米材料在环境检测中的应用

作　者: Essy Kouadio Fodjo
导　师: 龙亿涛
学　校: 华东理工大学
专　业: 分析化学
关键词: MWCNTs/SPE Nitrophenol isomers detection SERS substrate Electrochemistry Pollutant detection
分类号: X830.2
类　型: 博士论文
年　份: 2013年
下　载: 159次
引　用: 0次
阅　读: 论文下载

内容摘要

随着工业社会的发展,环境污染问题日益严重,已经成为世界各国特别是发展中国家面临的共同课题之一。有效的环境检测技术设备可为环境污染治理提供有力的技术支持,也是实现环境安全、促进社会可持续发展的迫切要求之一。研究发现,电化学和表面增加拉曼光谱(SERS)传感器有望在环境污染监测中发挥重要作用。本工作基于电化学和表面增强拉曼光谱(SERS)技术,研究制备了新型传感器,并将其用于环境污染物检测,研究工作主要包括以下几个方面：1.利用多壁碳管(MWCNT)修饰丝网印刷电极,制备了新型可抛式电化学传感器,并将其用于硝基酚污染物检测。研究结果表明,通过MWCNT修饰丝网印刷电极的工作电极,可增强电极的工作特性,这种组装方式获得的电极可用来检测电氧化峰相近的硝基酚的同分异构体；由于MWCNT的高表面积可以提高丝网印刷电极与待测溶液的接触面积,使得该电极对硝基酚同分异构的峰响应灵敏提高、分辨性强增强；并且,MWCNT可通过增加电子转移来提高检测物的电化学活性,其修饰的丝网印刷电极可用于对环境类电化学物质的检测。2.利用钒酸盐并通过将Ag/(3-AgVO3沉积在Cu基体上,制备了Cu@Ag/(3-AgVO3表面增强拉曼光谱活性基底,并以此来检测氨基甲酸酯类农药。研究结果显示,常规银胶对此类农药有着较弱的SERS活性,而我们制备的Cu@Ag/β-AgVO3基底对此类农药(西维因,卡巴呋喃,异丙威和残杀威)响应灵敏,对部分农药污染物的检测灵敏度可达pM水平。这主要得益于Cu@Ag/β-AgVO3基底更大的比表面积和更多的SERS“热点”,从而使其具有很高的SERS活性。此外,所制备的SERS活性基底也具有很好的稳定性及重复性。3.以葡萄糖为催化剂,利用水热法成功合成了双星状的钼酸银(Ag/α-MoO3, Ag/h-MoO3, Ag/β-MoO3, Ag2Mo2O7, and Ag2MoO4)基底,该合成方法使用七水钼酸铵和硝酸银为反应试剂、葡萄糖和半胱胺为催化剂。系统的实验结果显示,选用半胱胺作为催化剂,可以在室温下制备出Ag/α-MoO3。相比于以前的方法,该方法具有反应条件温和、反应时间短等优点。其中,催化剂的加入可以降低反应温度,减少反应时间。此外,实验通过XRD,Raman, TEM表征了制备的纳米材料,并将其作为SERS传感器用于抗坏血酸、苯胺、盐酸多巴胺和对苯二胺及它们混合物的检测。结果表明,此种方法制备的纳米材料具有高的灵敏度和高稳定性。总体研究结果表明,本论文研制的电化学和SERS传感器具有制备简便、检测灵敏度高等优点,因此可用于环境保护、化学和医药工业等紧急污染事件的便携快速检测分析。

全文目录

摘要  5-6
Abstract  6-8
Resume  8-13
Chapter 1:General Introduction  13-23
  1.1 Electrochemical sensors  14-17
    1.1.1 Multi-walled carbon nanotubes (MWCNTs)  14-15
    1.1.2 MWCNTs modified screen-printed electrode (SPE)  15-17
  1.2 Raman spectroscopy  17-22
    1.2.1 Localized surface Plasmon resonance (LSPR) and choice of Ag nanoparticles in SERS  18-20
    1.2.2 Chemical contribution in SERS enhancement  20-21
    1.2.3 Choice of wavelength in SERS  21
    1.2.4 SERS substrates  21-22
  1.3 Aims and Objectives of the Study  22-23
Chapter 2:Simultaneous determination of nitrophenol isomers based on MWCNTs/SPE  23-39
  2.1 Introduction  23-24
  2.2 Materials and Methods  24-26
    2.2.1 Rea(?)ents  24
    2.2.2 Apparatus and fabrication of MWCNTs/SPE  24-26
  2.3 Results and Discussion  26-37
    2.3.1 MWCNTs amount required for SPE modification  26
    2.3.2 Voltammetric behaviors of the nitrophenol isomers at MWCNTs/SPE  26-28
    2.3.3 Influence of scan rate  28-30
    2.3.4 Influence of pH  30-34
    2.3.5 Interferences  34
    2.3.6 Simultaneous determination of nitrophenol isomers  34-36
    2.3.7 Applications in real water samples  36-37
  2.4 Conclusions  37-39
Chaper 3:Cu@Ag/β-AgVO_3 as SERS substrate for the detection of carbamate pesticides  39-55
  3.1 Introduction  39-40
  3.2 Materials and Methods  40-41
    3.2.1 Reagents and Apparatus  40
    3.2.2 Synthesis of Ag/β-AgVO_3 nanobelts and preparation of Cu@Ag/β-AgVO_3 substrate  40-41
    3.2.3 Preparation of AgNPs and TLC-SERS  41
  3.3 Results and discussion  41-54
    3.3.1 Characterization of synthesized product  41-44
    3.3.2 Cu foil immersion time required for Cu@Ag/β-AgVO_3 fabrication  44-45
    3.3.3 The carbamate pesticides SERS behavior on different substrates  45-46
    3.3.4 Estimation of Cu@Ag/β-AgVO_3 enhancement and band assignment  46-49
    3.3.5 pH effect on the pesticides SERS activity  49-50
    3.3.6 Effect of ionic and organic compounds  50-51
    3.3.7 Repeatability and stability of Cu@Ag/β-AgVO_3  51-52
    3.3.8. Quantitative analysis of the carbamate pesticides detection  52-54
    3.3.9 Applications in real water samples  54
  3.4 Conclusions  54-55
Chapter 4:Low Temperature Synthesis of Silver Molybdenum Oxides  55-67
  4.1 Introduction  55
  4.2 Materials and Methods  55-57
    4.2.1 Reagents and apparatus  55-56
    4.2.2 Synthesis of Ag_xMo_yO_z  56
    4.2.3 Synthesis of silver nanoparticles and preparation of Ag/Ag_2MoO_4  56-57
    4.2.4 Characterization  57
  4.3 Results and discussion  57-66
    4.3.1 Synthesis of Ag_xMo_yO_z using glucose as the catalyst  57-64
      4.3.1.1 Required temperature and time of hydrothermal treatment  57-58
      4.3.1.2. Amount of glucose (Glc) and silver nitrate required  58-59
      4.3.1.3 Synthesis of Ag_xMo_yO_z and effect of reaction media pH  59-64
    4.3.2 Synthesis of Ag/α-MoO_3 using cysteamine as catalyst  64-65
    4.3.3 Conversion of Ag_xMo_xO4x-1 (Ag/α-MoO_3, Ag/β-MoO_3, Ag/h-MoO_3 and Ag_2MoO_7) phases to Ag/Ag_2MoO_4  65-66
  4.4 Conclusion  66-67
Chapter 5:Fabrication and Application of Si@Ag/Ag_2MoO_4 sensor as SERS substrate  67-79
  5.1 Introduction  67
  5.2 Materials and Methods  67-68
    5.2.1 Reagents and apparatus  67-68
    5.2.2 Preparation of Ag/Ag_xMo_yO_z coated Si wafer and samples for SERS measurement  68
    5.2.3 Characterization  68
  5.3 Results and Discussion  68-77
    5.3.1 Amount of Ag/Ag_2MoO_4 required for Si@Ag/Ag_2MoO4 fabrication  68-69
    5.3.2 Comparison of SERS activity of Si@Ag/Ag_2MoO_4 fabricated using different Ag_xMo_yO_z  69-71
    5.3.3 Repeatability and stability of Si@Ag/Ag_xMo_yO_z  71-72
    5.3.4 Ability of retention of Si@Ag_2MoO_4  72-73
    5.3.5 Quantification of Si@Ag/Ag_4MoO_4  73-74
    5.3.6 Determination of target molecules in complex analyte mixtures  74-77
  5.4 Conclusion  77-79
Chapter 6:Summary and Conclusions  79-81
References  81-97
List of publications  97-99
Acknowledgement  99

纳米材料在环境检测中的应用

内容摘要

全文目录

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