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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (24): 2969-2974.DOI: 10.6023/A1105312 上一篇    下一篇

研究论文

CdTe量子点与L-天冬氨酸相互作用的研究及其分析应用

刘正清, 刘绍璞, 闫曙光, 殷鹏飞, 何佑秋*   

  1. (发光与实时分析教育部重点实验室 西南大学化学化工学院 重庆 400715)
  • 投稿日期:2011-05-31 修回日期:2011-07-14 发布日期:2011-08-17
  • 通讯作者: 何佑秋 E-mail:heyq@swu.edu.cn
  • 基金资助:

    发光与实时分析重庆市重点实验室(西南大学)资助项目

Interaction between GSH-CdTe QDs and L-Aspartic Acid and Its Analytical Application

LIU Zheng-Qing, LIU Shao-Pu, YAN Shu-Guang, YIN Peng-Fei, HE You-Qiu   

  1. (School of Chemistry and Chemical Engineering, Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, Southwest University, Chongqing 400715)
  • Received:2011-05-31 Revised:2011-07-14 Published:2011-08-17

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水相中合成了谷胱甘肽(GSH)修饰的CdTe量子点(GSH-CdTe QDs). 利用紫外-可见吸收光谱(UV-vis)、共振瑞利散射(RRS)光谱、荧光光谱(FL)和傅里叶变换红外光谱(FTIR)研究了GSH-CdTe QDs与L-天冬氨酸(L-Aspartic acid, L-Asp)的相互作用机理. 在pH为5.3 的BR缓冲溶液中, GSH-CdTe QDs与L-Asp主要通过静电引力和氢键作用在GSH-CdTe QDs周围形成了粒径较大的聚集体, 导致体系的RRS显著增强和GSH-CdTe QDs的荧光急剧猝灭. 在一定浓度范围内RRS增强和荧光猝灭均与L-Asp的浓度成正比, 其中RRS法灵敏度更高（对L-Asp检出限为14.2 ng•mL–1）, 据此建立了以GSH-CdTe QDs作RRS探针测定L-Asp的一种新方法. 同时讨论了反应条件和共存物质对体系RRS强度的影响. 用于实际尿样中L-Asp的测定, 实验结果满意.

关键词: GSH-CdTe QDs, L-天冬氨酸, 紫外-可见吸收, 共振瑞利散射, 荧光

Glutathione (GSH) capped CdTe quantum dots (GSH-CdTe QDs) were synthesized in aqueous solution. The mechanism of interaction between GSH-CdTe QDs and L-Aspartic acid (L-Asp) was studied by UV-vis absorption，resonance Rayleigh scattering (RRS), fluorescence and infrared spectra. In pH 5.3 BR buffer solution, L-Asp could be combined with the GSH-CdTe QDs by the electrostatic attraction and hydrogen bond, forming a bigger diameter aggregate, which resulted in RRS increased markedly and the fluorescence of GSH-CdTe QDs quenched sharply. The increased RRS intensity and the quenched fluorescence intensity were directly proportional to the concentration of L-Asp in a certain range and the sensitivity of RRS method was higher (the detection limit for L-Asp was 14.2 ng•mL–1) than the fluorescence method, so a new sensitive RRS method for the determination of L-Asp was established by using GSH-CdTe QDs as a probe. In addition, the optimum conditions of the reaction and the influences of coexisting substances were tested by RRS method, which could be satisfactorily applied to the determination of L-Asp residues in urine samples.

Key words: GSH-CdTe QDs, L-Aspartic acid, UV-vis absorption, resonance Rayleigh scattering, fluorescence