金属纳米团簇与碳点荧光探针制备、组合与应用
发布时间：2018-09-09 13:01
【摘要】：本论文以荧光金属纳米团簇和碳点为研究对象,利用生物矿化法、高温热解法等策略制备了多种金属纳米团簇、碳点及复合荧光纳米传感材料,考察其结构、稳定性、荧光传感性能,发展了几种光学探针用于有机小分子和重金属离子的含量检测方法,揭示探针与分析物的相互作用机理,实现多种痕量目标分析物的特异性敏感检测,并探讨其在实际环境中的应用。本论文主要研究内容如下:(1)基于铜纳米团簇的曲酸生物传感器:以蛋白包覆的铜纳米团簇为荧光探针,以曲酸为检测对象,通过稳瞬态荧光光谱和紫外可见吸收光谱研究二者相互作用机制。研究结果表明,曲酸对铜纳米团簇的荧光猝灭机制为静态猝灭;铜纳米团簇中铜元素呈现多价态,曲酸与其中二价铜离子发生特异性反应生成曲酸铜沉淀,进而使铜纳米簇荧光猝灭。基于该作用机制,在最佳检测条件下,建立曲酸的荧光分析法。(2)基于金纳米团簇的荧光和共振光散射双模式检测植酸:采用溶菌酶为模板制备的金纳米团簇作为荧光和共振光散射探针,以植酸为检测对象,重点研究溶菌酶包覆金纳米团簇与植酸相互作用后共振光散射光谱和荧光光谱变化,分析植酸对溶菌酶包覆金纳米团簇粒径分布和形貌的影响机制,剖析二者相互作用机理。结果表明,植酸可以诱导生成包含有多个单分散金纳米簇的聚集体结构,从而引起了荧光的猝灭和共振光散射信号的显著增强。(3)碳点荧光“关-开”模式检测植酸:以柠檬酸和赖氨酸为原料制备荧光碳点,考察碳点、碳点/铁离子和碳点/铁离子/植酸体系的稳瞬态荧光光谱性质变化,构建基于碳点荧光“关—开”模式的植酸检测方法,并考察方法的稳定性、特异性、检测范围和检测限。综合Zeta电位、荧光衰减和共振光散射多种分析手段对荧光恢复机理进行分析。研究结果表明,植酸与碳点竞争结合铁离子,通过抑制碳点与铁离子之间的光诱导电子转移过程,实现荧光恢复。(4)双发射比率型荧光传感体系:制备碳点掺杂的二氧化硅粒子与蛋白质稳定的金纳米团簇,通过化学交联两种荧光纳米材料,形成单一激发波长下可发射双荧光的复合纳米粒子,并将其发展为Hg~(2+)浓度测定的比率型荧光探针;进一步,将双发射比率型荧光探针与分子印迹技术相结合,在双发射纳米粒子表面生长印迹层,构建分子印迹比率型荧光探针,并将其应用于环境污染物对硝基苯酚的选择性测定。
[Abstract]:In this paper, a variety of metal nanoclusters, carbon points and composite fluorescent nanosensors were prepared by biomineralization and pyrolysis, and their structures and stability were investigated. Fluorescence sensing properties. Several optical probes have been developed for the detection of organic small molecules and heavy metal ions. The mechanism of interaction between the probes and the analytes has been revealed, and the specific sensitive detection of trace target analytes has been realized. Its application in practical environment is also discussed. The main contents of this thesis are as follows: (1) kojic acid biosensor based on copper nanoclusters: protein coated copper nanoclusters are used as fluorescent probes, and kojic acid is used as the detection object. The mechanism of interaction between the two was studied by steady transient fluorescence spectroscopy and UV-Vis absorption spectra. The results showed that the fluorescence quenching mechanism of kojic acid on copper nanoclusters was static quenching. Furthermore, the fluorescence quenching of copper nanoclusters was observed. Based on this mechanism, under the best detection conditions, Fluorescence analysis of kojic acid was established. (2) phytic acid was detected based on fluorescence and resonance light scattering (RLS) of gold nanoclusters: gold nanoclusters prepared by lysozyme were used as fluorescence and resonance light scattering probes, phytic acid was used as the detection object. The changes of resonance light scattering (RLS) spectra and fluorescence spectra after the interaction of lysozyme coated gold nanoclusters with phytic acid were studied. The mechanism of phytic acid affecting the particle size distribution and morphology of lysozyme coated gold nanoclusters was analyzed. The results show that phytic acid can induce the formation of aggregates containing a number of monodisperse gold nanoclusters. The quenching of fluorescence and the enhancement of resonance light scattering signal were induced. (3) carbon spot fluorescence "off on" mode was used to detect phytic acid: fluorescent carbon points were prepared from citric acid and lysine, and carbon points were investigated. The stable transient fluorescence spectra of carbon spot / iron ion and carbon point / iron ion / phytic acid system were changed. A method of phytic acid detection based on the "on-off" mode of carbon spot fluorescence was constructed, and the stability, specificity, detection range and detection limit of the method were investigated. The mechanism of fluorescence recovery was analyzed by Zeta potential, fluorescence attenuation and resonance light scattering. The results show that phytic acid competes with carbon point to bind iron ion, which inhibits the photoinduced electron transfer process between carbon point and iron ion. (4) double emission ratio fluorescence sensing system: carbon dot-doped silica particles and protein stable gold nanoclusters were prepared by chemical crosslinking of two kinds of fluorescent nanomaterials. The composite nanoparticles which can emit double fluorescence at a single excitation wavelength were formed and developed into a ratio fluorescent probe for the determination of Hg~ (2) concentration. Further, the double emission ratio fluorescence probe was combined with molecular imprinting technique. A molecularly imprinted ratio fluorescent probe was constructed on the surface of double emission nanoparticles and applied to the selective determination of p-nitrophenol, an environmental pollutant.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：O657.3;TB383.1
，
本文编号：2232449
[Abstract]:In this paper, a variety of metal nanoclusters, carbon points and composite fluorescent nanosensors were prepared by biomineralization and pyrolysis, and their structures and stability were investigated. Fluorescence sensing properties. Several optical probes have been developed for the detection of organic small molecules and heavy metal ions. The mechanism of interaction between the probes and the analytes has been revealed, and the specific sensitive detection of trace target analytes has been realized. Its application in practical environment is also discussed. The main contents of this thesis are as follows: (1) kojic acid biosensor based on copper nanoclusters: protein coated copper nanoclusters are used as fluorescent probes, and kojic acid is used as the detection object. The mechanism of interaction between the two was studied by steady transient fluorescence spectroscopy and UV-Vis absorption spectra. The results showed that the fluorescence quenching mechanism of kojic acid on copper nanoclusters was static quenching. Furthermore, the fluorescence quenching of copper nanoclusters was observed. Based on this mechanism, under the best detection conditions, Fluorescence analysis of kojic acid was established. (2) phytic acid was detected based on fluorescence and resonance light scattering (RLS) of gold nanoclusters: gold nanoclusters prepared by lysozyme were used as fluorescence and resonance light scattering probes, phytic acid was used as the detection object. The changes of resonance light scattering (RLS) spectra and fluorescence spectra after the interaction of lysozyme coated gold nanoclusters with phytic acid were studied. The mechanism of phytic acid affecting the particle size distribution and morphology of lysozyme coated gold nanoclusters was analyzed. The results show that phytic acid can induce the formation of aggregates containing a number of monodisperse gold nanoclusters. The quenching of fluorescence and the enhancement of resonance light scattering signal were induced. (3) carbon spot fluorescence "off on" mode was used to detect phytic acid: fluorescent carbon points were prepared from citric acid and lysine, and carbon points were investigated. The stable transient fluorescence spectra of carbon spot / iron ion and carbon point / iron ion / phytic acid system were changed. A method of phytic acid detection based on the "on-off" mode of carbon spot fluorescence was constructed, and the stability, specificity, detection range and detection limit of the method were investigated. The mechanism of fluorescence recovery was analyzed by Zeta potential, fluorescence attenuation and resonance light scattering. The results show that phytic acid competes with carbon point to bind iron ion, which inhibits the photoinduced electron transfer process between carbon point and iron ion. (4) double emission ratio fluorescence sensing system: carbon dot-doped silica particles and protein stable gold nanoclusters were prepared by chemical crosslinking of two kinds of fluorescent nanomaterials. The composite nanoparticles which can emit double fluorescence at a single excitation wavelength were formed and developed into a ratio fluorescent probe for the determination of Hg~ (2) concentration. Further, the double emission ratio fluorescence probe was combined with molecular imprinting technique. A molecularly imprinted ratio fluorescent probe was constructed on the surface of double emission nanoparticles and applied to the selective determination of p-nitrophenol, an environmental pollutant.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：O657.3;TB383.1
，
本文编号：2232449
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