【作者】 张烨；

【导师】 黄红梅；

【作者基本信息】 湖南师范大学 ， 分析化学， 2014， 硕士

【摘要】 金、银纳米粒子因具有独特的光学、电学、化学性质及潜在价值,在材料、信息及生命科学等领域显示出广阔的应用前景。因而金、银纳米粒子及其复合材料的制备与应用已经成为了当今科学研究的热点领域之一。本文合成了水溶性共轭聚合物稳定的新型银纳米复合材料和柠檬酸钠稳定的均一金纳米粒子,通过与羧基芘衍生物荧光探针之间的作用,分别构建了可用于碘离子、生物硫醇及硫氰根灵敏检测的传感体系。具体的研究内容包括以下三个部分:(1)以含吡啶基团的水溶性共轭聚合物P1为稳定剂,原位生长法合成了聚合物/银纳米复合材料P1-AgNPs,并利用P1-AgNPs对羧基芘衍生物probe1的内滤作用猝灭芘衍生物的荧光,通过双氧水(H2O2)存在下加入碘离子(I-),氧化蚀刻P1-AgNPs使其等离子体吸收带衰减,而削弱内滤效应使得芘衍生物的荧光恢复,以此实现碘离子的高灵敏检测。该方法对碘离子的最低检测浓度可达5.0×10-10M。(2)以柠檬酸钠为稳定剂和还原剂合成了金纳米粒子(AuNPs),利用羧基芘衍生物probe1吸附在金纳米粒子表面并与金纳米粒子表面之间的能量转移作用猝灭芘衍生物的荧光,当加入硫醇生物分子,通过硫醇分子与金纳米粒子间的共价结合作用迫使probe1远离金纳米,从而阻断能量转移的途径达到荧光恢复的效果,基于此现象构建了灵敏检测硫醇分子的方法。该方法对谷胱甘肽、半胱氨酸和高半胱氨酸的最低检测浓度均可达1.0×10-9M。(3)基于柠檬酸钠稳定的金纳米粒子(AuNPs)和羧基芘衍生物(probe1)体系检测硫氰根离子。利用硫氰根能以非共价方式吸附于金纳米粒子的表面,通过竞争反应使得芘衍生物远离金纳米粒子表面,而最终使芘衍生物被金纳米粒子猝灭的荧光得到恢复。基于这个现象构建了一种简便、快速检测硫氰根的方法。该方法对硫氰根的最低检测浓度可达3.0×10-7 M。更多还原

【Abstract】 Gold and silver nanoparticles have been widely applied in fields of material,information and life science due to their particular optical,electric and chemical properties.Thus,the preparation and application of gold and silver nanoparticles and their composites have become one of the hot research topics in modern science.In this paper,new water-soluble conjugated polymer stablized-silver nanoparticles and sodium citrate protected-gold nanoparticles were synthesized.Based on the interaction between gold or silver nanoparticles and pyrene derivative probe,we systematically investigated the fluorescence sensing of iodide,biothiols and thiocyanate with high sensitivity.The following is the main contents of my dissertation:(1)P1,a novel conjugated polymer with specific coordinating pyridyl segments,was chosen as the protective agent for AgNPs.The P1-AgNPs prepared by in situ synthesis.The intense fluorescence of probe 1 can be quenched owing to the inner-filter effect(IFE)of P1-AgNPs on pyrene derivative(probe 1).Then the intense fluorescence of probe1 quenched by P1-AgNPs can be efficiently recovered after the addition of H2O2and I-via the Pl-AgNPs oxidation-etching and damping of surface plasmon band.The lowest detectable concentrations of I-using this method was 5.0×10-10 M.(2)The AuNPs were prepared through Frens method coated with citrate.The fluorescence of pyrene derivative(probe 1)absorbed on the surface of the gold nanoparticles gets quenched owing to the surface energy transfer from the probe 1 to the gold nanoparticles.After addition of biothiols,the strong covalent combination between the mercapto group of biothiols and gold nanoparticles drives probe 1 away from the gold nanoparticles’surface,which block the pathway of energy transfer between probe 1 and gold nanoparticles.Based on this phenomenon,we build a sensitive method for biothiols detection.The lowest detectable concentrations of biothiols using this method was 1.0×10-9 M.(3)A convenient fluorescent sensor based on the citrate coated AuNPs and pyrene derivative(probe 1)was demonstrated for thiocyanate(SCN-).As mentioned,the fluorescence of pyrene derivative(probe 1)was quenched by gold nanoparticles.With addition of SCN-,SCN-absorbs on the surface of AuNPs with non-covalent means which drives probe 1 away from the gold nanoparticles’ surface though competition response between SCN-and probe 1.As a result,the intense fluorescence of probe1 quenched by AuNPs can be efficiently recovered.Based on this phenomenon,we build a simple and sensitive method for SCN-detection.The lowest detectable concentrations of SCN-using this method was 3.0×10-7M.更多还原