组氨酸、谷胱甘肽混合修饰金纳米团簇的光稳定性研究  

Study on the Photostability of Histidine and Glutathione Modified Gold Nanoclusters

作　　者：周优 谭洪鹏 唐爽 胡振苹 梁建功[1] 任国兰[1] ZHOU You;TAN Hong-peng;TANG Shuang;HU Zhen-ping;LIANG Jian-gong;REN Guo-lan(College of Science,Huazhong Agricultural University,Wuhan 430070,China)

机构地区：[1]华中农业大学理学院,湖北武汉430070

出　　处：《光谱学与光谱分析》2018年第10期3177-3181,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(31372439);国家大学生创新实验项目(201710504093)资助

摘　　要：金纳米团簇(简称金簇)由几到几百个金原子及修饰试剂组成,由于其尺寸接近于电子费米波长,表现出良好的发光特性及生物相容性,是一类新型纳米标记探针。目前,金纳米团簇在生物检测、细胞成像、癌症诊断及治疗等领域受到研究者的广泛关注。然而,对于光照条件下金簇的稳定性还不清楚。在合成组氨酸、谷胱甘肽混合修饰金簇的基础上,系统研究了光照条件下金簇在不同pH(5.0,7.4和9.0)的荧光变化规律,结果表明,在氙灯强光照射下,金纳米团簇的荧光会随着照射时间的增加逐渐降低,在pH 9.0条件下比pH 5.0及7.4时降低更快,说明金簇在pH 5.0及7.4时光稳定性更好。在此基础上,采用紫外-可见吸收光谱、红外光谱等手段研究了光照前后金簇表面基团的变化规律,发现光照后金簇的紫外可见吸收光谱及红外光谱均发生了明显的变化,说明光照导致金簇表面修饰基团发生了变化。当向体系中通入氮气后,金簇最大发射波长处荧光强度随照射时间的变化明显变慢,说明金簇表面基团与溶液中溶解氧发生了反应,导致金簇表面电荷及修饰试剂状态发生变化,从而导致金簇荧光产生猝灭。相关研究结果对于金纳米团簇在生命科学及分析化学等领域的进一步应用具有一定的参考价值。Gold nanoclusters(Au NCs)consists of a few to several hundred gold atoms and modified reagents,is a new kind of labeled nanoprobes,which have good luminescent properties and biocompatibility due to its size close to the electron Fermiwavelength.Up to now,gold nanoclusters have attracted wide attention in thefields of biological detection,cell imaging,cancer diagnosis and treatment.However,the stability of gold nanoclusters under irradiation condition is still unclear.In this manuscript,histidine and glutathione modified gold nanoclusters were prepared,and the fluorescence changes of gold nanoclusters under theirradiation conditions at different pH(5.0,7.4 and 9.0)were investigated.The results show that the fluorescence of gold nanoclusters decreases with the increase of irradiation time of xenon light,which is decreased faster at pH=9.0 than that at pH=5.0 and 7.0,indicating that the gold nanoclusters havebetter light photostability at pH=5.0 and 7.4.On this basis,the changing rule of surface groups of gold nanoclusters before and after irradiation were studied by UV-Vis absorption spectrum and Infrared spectrum.The results showed that the UV-Vis absorption spectrum and Infrared spectrum of the gold nanoclusterschange obviously after irradiation,indicating irradiation leads to changes insurface modified groups of gold nanoclusters.When nitrogen is introduced intothe system,the fluorescence intensity atλmax wavelength of the gold nanoclusters changed more slowly with the irradiation time than that withoutnitrogen,indicating that the surface groups of the gold nanoclusters react with the dissolved oxygen in the solution,resulting in changes of the surface charge and the condition of modified reagents,then leading to reducting the fluorescence intensity of gold nanoclusters.The results of this study have some reference value for the further application of gold nanoclusters in life sciences andanalytical chemistry.

关 键 词：金纳米团簇 光稳定性 组氨酸 谷胱甘肽 

分 类 号：O641[理学—物理化学]