【作者】 王磊；

【导师】 刘应凡；

【作者基本信息】 郑州轻工业学院 ， 化学工程与技术， 2015， 硕士

【摘要】 含Ag量子点是一种三维尺寸介于1~10 nm新型的无机半导体发光纳米微晶,具有光化学稳定性好、宽激发光谱和生物相容性好的优点,已广泛应用在生物医学、重金属检测荧光探针等领域。尤其是,相比传统有机染料作为荧光标记探针,含Ag量子点展现出诸如光化学稳定性好、长效光学性质以及不易被降解等优点。另外,伴随着工业大繁荣大发展,重金属已广泛分布于人类赖以生存的自然界中,给人类健康和环境带来极大的危害。传统检测Hg2+等重金属离子采用的是测试分析繁琐、复杂以及冗长且需要昂贵复杂仪器的电化学方法、高效液相色谱法等。开发快捷、经济环保的重金属离子检测方法对人们身体健康和环境保护起着里程碑的意义。新兴的快速、经济的检测重金属离子方法—半导体含Ag量子点光化学传感器逐渐受到环境科学领域关注。本论文所合成各种含Ag量子点均在水相下合成。由此基础上,讨论了含Ag量子点的合成以及Ag2S-Zn作为Hg2+离子荧光探针的应用。论文主要研究内容归纳如下:1、采用一种简便快捷的制备纳米材料的方法—光还原法合成以d-青霉胺、l-青霉胺为配体的Ag量子点。青霉胺@Ag量子点展现出尺寸均一、荧光强且在环境中稳定存在的特性,其手性特征可通过改变紫外光照射时间来控制。同时,溶血试验显示,青霉胺@Ag量子点比TGA@Cd Te量子点有更好的生物相容性。2、利用快捷的60℃水相“一步法”合成d-青霉胺@Ag2S-Zn量子点。采用透射电子显微镜(TEM)、紫外-吸收光谱(UV-vis)和荧光光谱(PL)对其进行了表征。并开展了将d-青霉胺@Ag2S-Zn量子点作为荧光探针检测重金属Hg2+的应用研究。利用在Hg2+存在d-青霉胺@Ag2S-Zn量子点体系中,随着Hg2+的浓度增加体系荧光光谱在波长512 nm处的散射峰强度逐渐增强。同时,研究了共存离子如K+,Na+,Zn2+,Mg2+,Ca2+,Cu2+,Ba2+和Sr2+等离子对体系荧光特性并无影响。故而,设计出了一种新型无毒、绿色环保的检测Hg2+的荧光探针。3、120℃下水热反应下合成DHLA@Ag2S量子点。通过因素分析法找到最佳反应条件是:nDHLA:nAg NO3:nTAA=50:1:0.5,p H值=9.0。所合成的DHLA@Ag2S量子点在波长为885 nm处出现近红外光致发光,并且随着反应时间增加,DHLA@Ag2S量子点在此波长下的荧光强度逐渐增加。反应时间为180 min达到最大值。通过紫外可见光谱图看出随着取样时间的延长发生了红移,表明所合成的DHLA@Ag2S量子点粒径在逐渐变大。另外通过XRD和TEM可以看出,所制备的DHLA@Ag2S量子点为单斜晶型,且粒径约为7 nm;Zeta电位和粒径分布表征说明所合成出来的DHLA@Ag2S量子点是带负电荷,粒径分布稳定性能良好。最后,XPS图谱和EDX能谱分析展现所合成的DHLA@Ag2S量子点中的元素。尤其是,所制备的DHLA@Ag2S量子点在近红外光区(波长为885 nm处)光致发光。更多还原

【Abstract】 Quantum dots(QDs) containing with Ag is a three-dimensional size between 1~10 nm novel inorganic semiconductor light-emitting nanocrystals with benefits as photochemical stability, broad excitation spectrum and good biocompatibility, it is widely used in biological cell imaging fluorescent probes, chemical sensors and other fields. In particular, compared to conventional organic dye, QDs containing with Ag as a fluorescent-labeled probes exhibit good photochemical stability, long-lasting and difficult to be degraded optical properties and so on. In addition, along with industrial development and prosperity, heavy metals are widely distributed in the nature of human survival, caused great harm to human health and environment. Traditional detection of heavy metal ions(Hg2+) test analysis method is cumbersome, complex and lengthy and requires expensive, such as complicated equipment electrochemical methods, high performance liquid chromatography. So it is important for human to find economical and convenient method for the detection of heavy metal ions. Emerging fast and economical method for the detection of heavy metal ions- semiconductor QDs containing with Ag photochemical sensor gradually being concerned about environmental science. In this paper, Synthesis of QDs containing with Agusing water-soluble, and discuss the synthesis of the QDs containing with Ag and Ag2S-Zn QDs as the applications of Hg2+ ion fluorescence probe. The main research contents are summarized as follows:1. The photoreduction synthesis of Ag QDs with d-penicillamine, l-penicillamine as ligand. Pen@Ag QDs exhibit uniform size, fluorescence intensity and stable in the environment characteristics, the chiral of pen@Ag QDs can be controlled by changing the UV irradiation time. Meanwhile, hemolysis test showed pen@Ag QDs have better biocompatibility than TGA@Cd Te QDs.2. Using 60 ℃ water phase synthesis of d-pen@Ag2S-Zn QDs. Transmission electron microscopy(TEM), UV absorption spectrum(UV-vis) and fluorescence spectra(PL) were characterized. And we carried out applied research about d-pen@Ag2S-Zn QDs for the detection of heavy metals Hg2+ as fluorescent probes. Using the presence of Hg2+ and d-pen@Ag2S-Zn QDs system, the fluorescence spectra in the scattering peak intensity at a wavelength of 512 nm gradually increased along with Hg2+ concentration increases. Meanwhile, the study of other ions such as K+, Na+, Zn2+, Mg2+, Ca2+, Cu2+, Ba2+ and Sr2+ has no effect on the fluorescence properties. Therefore, we designed a new type of non-toxic, green fluorescent probes to detect Hg2+.3. 120 ℃ hydrothermal synthesis of DHLA@Ag2S QDs. To find the optimal reaction conditions by factor analysis are: nDHLA: nAg NO3: nTAA = 50:1:0.5, p H=9.0. Meanwhile, it can be seen from the fluorescent characterization, the max of reaction time was 180 min. UV-Vis spectra by the same sampling time can be seen as moving in the extension of the wavelength to a longer wavelength, i.e. red shift, it may be generated DHLA@Ag2S quantum dot particle diameter becomes larger. Further it can be seen by XRD and TEM, DHLA@Ag2S QDs are monoclinic type, and the particle diameter of approximately 7 nm; Zeta potentials and particle size distribution of DHLA Ag2 S QDs show negative charge, particle size distribution and stable good performance. Finally, EDX and XPS exhibit the elements of DHLA@Ag2S QDs. Particularly, DHLA@Ag2S QDs prepared in the near infrared region(at a wavelength of 885 nm) photoluminescence.更多还原