荧光手性银纳米簇的制备、表征及用于手性分子的检测研究
发布时间：2018-07-21 20:02
【摘要】：目前,很多研究者都对荧光和手性银纳米簇(AgNCs)的制备和应用特别感兴趣,并进行了大量的研究。但AgNCs的制备方法还有待进一步改进,同时关于AgNCs的荧光增强机理研究不够充分。利用AgNCs手性特性进行分析的研究较少,相关研究需要进一步探索。因此本文就荧光手性AgNCs的制备、表征及手性分子的检测进行了深入的研究。1.本论文使用外消旋谷胱甘肽((±)GSH)作为配体,通过固相研磨的方法成功合成了既有手性又有荧光的AgNCs。将硝酸银(AgNO3)和GSH固体混合,充分研磨后加入硼氢化钠(NaBH4)还原。反应完的固体混合物加入水和乙醇进行溶解,离心分离纯化后得到具有手性的AgNCs。进一步将AgNCs溶于水,孵育24h后得到同时具有强烈荧光和手性的AgNCs。实验对AgNCs的制备温度、配体比例、溶剂极性、溶剂pH等条件进行了优化。经过实验优化后的最佳制备条件为:温度27℃、GSH和AgNO3的比例为3:1、采用水作为溶剂、pH=5.2。2.实验进一步通过荧光(FL)、高分辨透射电子显微镜(HR-TEM)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、圆二色(CD)光谱和电喷雾电离质谱(ESI-MS)对合成的AgNCs进行表征。结果表明,实验中通过固相合成的方法成功制备了荧光手性AgNCs。制备的AgNCs平均粒径为1.68nm,主要组成为Ag4(SG)4。更有趣的是,实验中发现AgNCs粉末溶于水孵育过程中,其荧光明显增强且CD信号发生翻转。3.实验深入研究了AgNCs聚集诱导荧光增强(AIEE)和手性变化的特性,采用基质辅助激光解吸/电离时间飞行质谱(MALDI-TOF-MS)、荧光(FL)及CD光谱等技术来进行研究。结果发现,AgNCs表面连接的GSH之间形成氢键引起AgNCs的交联聚合,导致AIEE和手性变化的现象。4.将AgNCs用于D/L-青霉胺(D/LPA)、D/L-葡萄糖(D/L-Glu)和D/L-组氨酸(D/L-His)的检测。研究表明,制备的AgNCs可以选择性地与D构型的青霉胺、葡萄糖和组氨酸作用,导致荧光信号发生变化。然而,L构型的青霉胺、葡萄糖和组氨酸对制备的AgNCs的荧光基本无影响。同时,研究结果还表明,可运用AgNCs建立荧光传感进行组氨酸的定量分析,以及有望将其应用于温度传感。
[Abstract]:At present, many researchers are particularly interested in the preparation and application of fluorescent and chiral silver nanoclusters (AgNCs). However, the preparation method of AgNCs needs to be further improved, and the fluorescence enhancement mechanism of AgNCs is not sufficiently studied. There are few studies on chiral properties of AgNCs, which need to be further explored. Therefore, the preparation and characterization of fluorescent chiral AgNCs and the detection of chiral molecules were studied in this paper. In this paper, the chiral and fluorescent AgNCswere synthesized by solid phase grinding using racemic glutathione (卤) GSH) as ligand. Silver nitrate (Agno _ 3) and GSH were mixed and ground fully, then sodium borohydride (NaBH4) was added. The solid mixture was dissolved in water and ethanol and purified by centrifugation to obtain chiral AgNCs. AgNCs were further dissolved in water and incubated for 24 hours to produce both strong fluorescence and chiral AgNCs. The preparation temperature, ligand ratio, solvent polarity and solvent pH of AgNCs were optimized. The optimum preparation conditions were as follows: the ratio of GSH and Agno _ 3 was 3: 1 at 27 鈩，
本文编号：2136706
[Abstract]:At present, many researchers are particularly interested in the preparation and application of fluorescent and chiral silver nanoclusters (AgNCs). However, the preparation method of AgNCs needs to be further improved, and the fluorescence enhancement mechanism of AgNCs is not sufficiently studied. There are few studies on chiral properties of AgNCs, which need to be further explored. Therefore, the preparation and characterization of fluorescent chiral AgNCs and the detection of chiral molecules were studied in this paper. In this paper, the chiral and fluorescent AgNCswere synthesized by solid phase grinding using racemic glutathione (卤) GSH) as ligand. Silver nitrate (Agno _ 3) and GSH were mixed and ground fully, then sodium borohydride (NaBH4) was added. The solid mixture was dissolved in water and ethanol and purified by centrifugation to obtain chiral AgNCs. AgNCs were further dissolved in water and incubated for 24 hours to produce both strong fluorescence and chiral AgNCs. The preparation temperature, ligand ratio, solvent polarity and solvent pH of AgNCs were optimized. The optimum preparation conditions were as follows: the ratio of GSH and Agno _ 3 was 3: 1 at 27 鈩，
本文编号：2136706
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