水溶性CdTe量子点在金属离子检测中的尺寸效应  

Size Effects of Water-Soluble CdTe Quantum Dot in Metal Ion Detection Applications

作　　者：焦杭州 梁振华[1,2] 彭桂花[1,2] 周黄歆 

机构地区：[1]广西师范大学化学与药学学院,广西桂林541004 [2]广西师范大学药用资源化学与药物分子工程教育部重点实验室,广西桂林541004

出　　处：《广西师范大学学报（自然科学版）》2014年第2期106-110,共5页Journal of Guangxi Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(51102053)

摘　　要：以巯基乙酸作为修饰剂,控制原料比例、pH值、反应时间,合成了不同粒径的荧光CdTe量子点,通过对各个金属离子的响应测试发现:小粒径量子点均对汞离子表现出淬灭的现象,其他金属离子则无明显响应;而大粒径量子点则对银离子表现出明显的淬灭现象,其他金属离子则无明显响应,两种粒径的量子点对Hg^(2+)和Ag^(+)的检测限分别为8.7 nmol/L和9.9 nmol/L。Hg^(2+)与大小粒径量子点作用的不同现象可能是由于小粒径量子点具有较大淬灭半径所引起,而Ag^(+)与大小粒径量子点作用的不同现象可能是由于大粒径量子点与银离子作用后发生了电子转移过程。证明量子点对金属离子的响应不仅与量子点的修饰剂有关,还与其粒径大小有关。利用这种方法,实现了对Hg^(2+)和Ag^(+)良好的灵敏性和选择性检测。Different sizes of thioglycolic acid capped CdTe quantum dots were synthesized in aqueous so lution, the effects of their size on the sensitivity and selectivity in the fluorometric determination of met al ion were studied. It was found that the small sizes of QDs displayed no significant quenching or en hancement responses to most of the observed metal ions except Hg2＋ , while the QDs with large size dis played no significant quenching or enhancement responses to most of the observed metal ions except Ag~. The detection limits of Hg2＋ and Ag＋ were 8.7 nmol/L and 9.9 nmol/L, respectively. The differ ent phenomena that different size of QDs function with Hg2＋ may be due to the small size of QDs has a larger radius caused by quenching, and the phenomena of Ag＋ may be due to occurring transfer proces ses after the large size of the QDs function with Ag＋. This study illuminated unambiguously that im provement of sensing performance by the use of QDs could be achieved readily through finetuning their particle sizes and should be considered as an important factor for the development of QDs based probes.

关 键 词：水溶性 量子点 金属离子 检测 尺寸效应 

分 类 号：O657.39[理学—分析化学]