重金属双离子响应型贵金属纳米光学探针研究

发布时间：2018-01-22 10:34

本文关键词： 贵金属纳米光学探针 Cu2+ Mn2+ Cr3+ Cr2O72- 快速比色区分检测　出处：《安庆师范学院》2015年硕士论文　论文类型：学位论文

【摘要】：现代工业的快速发展和人类对资源的掠夺性开采导致重金属引起的水体环境污染严重。因此,实现对污染水体中重金属离子的快速灵敏检测,具有重要意义。目前,国内外检测污染水体中重金属离子的方法主要借助于精密分析仪器,然而这些方法存在检测费用昂贵、样品前处理复杂、检测时间较长等缺陷。贵金属纳米颗粒胶体的浓度、粒径大小及形貌变化都会引起其表面等离子体共振吸收发生变化,从而导致溶胶颜色发生改变。因此,通过裸眼比色或紫外可见吸收光谱分析可实现对水体中重金属离子的检测。已报道的基于贵金属纳米颗粒的光学探针通常只能实现对单一重金属离子的检测或对多种重金属离子同时检测但无法逐一区分;而实际环境水体中可能同时被两种或两种以上的重金属离子污染。为进一步拓展贵金属纳米光学探针的应用,本论文设计并研发了重金属双离子响应型贵金属纳米光学探针,通过对反应条件的调控,可实现对两种重金属离子的区分检测。具体研究内容如下:1)Cu2+/Mn2+响应型银纳米光学探针的研究:室温下以硼氢化钠还原制备出采用焦磷酸钠(Na4P2O7)和羟丙基甲基纤维素(HPMC)功能化的银纳米颗粒(Ag NPs),其粒径约为15 nm,在水溶液中的分散性良好。在酸性环境中,Ag NPs被Cu2+氧化刻蚀,导致溶胶颜色由亮黄色变为无色;在碱性环境中,P2O74-与Mn2+发生配位反应诱导Ag NPs发生团聚,导致溶胶颜色由亮黄色变为褐色。由此可实现对Cu2+和Mn2+的裸眼比色检测,检测限(LOD)分别为0.05μmol/L和0.5μmol/L,由于银纳米颗粒表面等离子体共振吸收也相应发生了变化,通过紫外可见分光光度计(UV-vis)可实现低浓度的定量检测,最低检测限分别为2.0 nmol/L和20nmol/L。此外,该银纳米光学探针对Cu2+和Mn2+具有优异的选择性,且已成功实现对实际环境水样的区分检测。2)Cr3+/Cr2O72-响应型金纳米光学探针的研究:以没食子酸还原并包裹制得功能化的金纳米颗粒(GA-Au NPs),其粒径约为30 nm,在水溶液中的分散性良好。在掩蔽剂硫代硫酸钠和柠檬酸钠存在下,该GA-Au NPs可实现对Cr3+的快速检测,无其他离子干扰;在掩蔽剂乙二胺四乙酸二钠(EDTA)的存在下,该GA-Au NPs可实现对Cr2O72-的快速检测,无其他离子干扰。通过对实验条件的优化,该金纳米光学探针对Cr3+和Cr2O72-具有优异的选择性和灵敏度。研究发现,铬离子(Cr3+和Cr2O72-)与没食子酸通过络合作用诱导Au NPs团聚,导致Au NPs溶胶颜色及表面等离子体共振吸收发生变化,根据该反应机理可实现对总铬离子的裸眼比色检测,检测限为1.5μmol/L,通过紫外可见分光光度计可实现对总铬离子低浓度的定量检测,检测限为0.05μmol/L。在掩蔽剂存在的条件下(硫代硫酸钠和柠檬酸钠掩蔽Cr2O72-实现对Cr3+的检测;EDTA掩蔽Cr3+实现对Cr2O72-的检测)可实现对Cr3+或Cr2O72-的检测,裸眼比色检测Cr3+和Cr2O72-的检测限分别为1.5μmol/L和2μmol/L,UV-vis检测限分别为0.1μmol/L和0.1μmol/L。此外,利用该金纳米光学探针实现了对实际环境水样中Cr3+和Cr2O72-的区分检测。
[Abstract]:The rapid development of modern industry and human resources of the predatory exploitation caused serious environmental pollution caused by heavy metals in water. Therefore, to achieve rapid and sensitive detection of heavy metal ions in polluted water, which is of great significance. At present, at home and abroad to detect the pollution of heavy metals in water from the method mainly depends on the precision analysis instruments, however these methods exist detection of expensive, complex sample preparation, detection time and other defects. The concentration of noble metal nanoparticles, particle size and morphology change will cause the surface plasmon resonance absorption changes, resulting in sol color change. Therefore, the naked eye color or UV Vis absorption spectrum analysis can be realized detection of heavy metal ions in water. The realization of optical probe of noble metal nanoparticles usually only on a single heavy metal ion based on the reported Detection of heavy metal ions or multiple simultaneous detection but cannot distinguish one by one; but the actual environment in water may also be two or more than two kinds of heavy metals pollution. In order to further expand the application of noble metal nano optical probe, this thesis presents the design and development of the heavy metal ion response double noble metal nano optical probe, through the regulation of the reaction conditions, can distinguish between detection of two kinds of heavy metal ions. The specific contents are as follows: 1) of silver nano optical probe response Cu2+/Mn2+ at room temperature by reduction of sodium borohydride was prepared using sodium pyrophosphate (Na4P2O7) and hydroxypropyl methyl cellulose (HPMC) silver nanoparticles functionalized (Ag NPs), and its diameter is about 15 nm, in aqueous solution with good dispersion. In the acidic environment, Ag NPs by Cu2+ oxidation etching, resulting in color changed from light yellow to colorless; in alkaline environment, P2O74- The coordination reaction induced by Ag NPs and Mn2+ together, resulting in the color changed from light yellow to brown. It can be realized on the Cu2+ and Mn2+ of the naked eye colorimetric detection, detection limit (LOD) were 0.05 mol/L and 0.5 mol/L, the silver nanoparticles surface plasmon resonance absorption have been changed and through the ultraviolet visible spectrophotometer (UV-vis) can realize the quantitative detection of low concentration, the minimum detection limit of 2 nmol/L and 20nmol/L. respectively. In addition, the silver nano optical probe has excellent selectivity to Cu2+ and Mn2+, and has been successfully achieved to detect.2 on the actual environmental samples) of gold nano optical probe the response of Cr3+/Cr2O72- to gold nanoparticles prepared and gallic acid reduction package functionalized (GA-Au NPs), the particle size is about 30 nm, in aqueous solution with good dispersion. In the presence of masking agent of sodium thiosulfate and Sodium Citrate under The GA-Au, NPs can achieve rapid detection of Cr3+, no other ion interference; masking agent in two sodium ethylenediaminetetraacetic acid (EDTA) in the presence of the GA-Au NPs can achieve the rapid detection of Cr2O72-, no other ion interference. By optimizing the experimental conditions, the gold nano optical probe has excellent selectivity and the sensitivity of Cr3+ and Cr2O72-. The study found that chromium ions (Cr3+ and Cr2O72-) and gallic acid by complexation induced by Au NPs in Au NPs sol agglomeration, color and surface plasmon resonance absorption changes, according to the reaction mechanism of total chromium ion uncorrected colorimetric detection, the detection limit is 1.5 mol/L, the UV VIS spectrophotometer can realize quantitative detection of total chromium ions of low concentration, the detection limit is 0.05 mol/L. in the presence of masking agent (sodium thiosulfate and sodium citrate to mask Cr2O72- Cr3+ to achieve the examination Test; EDTA masking Cr3+ achieve the detection of the Cr2O72-) can realize the detection of Cr3+ or Cr2O72-, the naked eye were 1.5 mol/L and 2 mol/L than the detection limit of color detection of Cr3+ and Cr2O72-, the detection limit of UV-vis were 0.1 mol/L and 0.1 mol/L. in addition, the gold nano optical probe is realized the detection of Cr3+ and Cr2O72- between the actual environmental samples.

【学位授予单位】：安庆师范学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O657.3;TB383.1

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