Shen Yizhong, Liu Shaopu, He Youqiu
School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, People's Republic of China.
Luminescence. 2014 Mar;29(2):176-82. doi: 10.1002/bio.2525. Epub 2013 May 3.
Water-soluble glutathione (GSH)-capped core/shell CdTe/CdS quantum dots (QDs) were synthesized. In pH5.4 sodium phosphate buffer medium, the interaction between GSH-CdTe/CdS QDs and sanguinarine (SA) was investigated by spectroscopic methods, including fluorescence spectroscopy and ultraviolet-visible absorption spectroscopy. Addition of SA to GSH-CdTe/CdS QDs results in fluorescence quenching of GSH-CdTe/CdS QDs. Quenching intensity was in proportion to the concentration of SA in a certain range. Investigation of the quenching mechanism, proved that the fluorescence quenching of GSH-CdTe/CdS QDs by SA is a result of electron transfer. Based on the quenching of the fluorescence of GSH-CdTe/CdS QDs by SA, a novel, simple, rapid and specific method for SA determination was proposed. The detection limit for SA was 3.4 ng/mL and the quantitative determination range was 0.2-40.0 µg/mL with a correlation coefficient of 0.9988. The method has been applied to the determination of SA in synthetic samples and fresh urine samples of healthy human with satisfactory results.
合成了水溶性谷胱甘肽（GSH）包覆的核壳型CdTe/CdS量子点（QDs）。在pH5.4的磷酸钠缓冲介质中，采用荧光光谱和紫外可见吸收光谱等光谱方法研究了GSH-CdTe/CdS量子点与血根碱（SA）之间的相互作用。向GSH-CdTe/CdS量子点中加入SA会导致GSH-CdTe/CdS量子点的荧光猝灭。在一定范围内，猝灭强度与SA的浓度成正比。对猝灭机理的研究表明，SA对GSH-CdTe/CdS量子点的荧光猝灭是电子转移的结果。基于SA对GSH-CdTe/CdS量子点荧光的猝灭作用，提出了一种新颖、简便、快速且特异的SA测定方法。SA的检测限为3.4 ng/mL，定量测定范围为0.2 - 40.0 µg/mL，相关系数为0.9988。该方法已应用于合成样品和健康人新鲜尿液样品中SA的测定，结果令人满意。
