Li Haibing, Wang Xiaoqiong
Key Laboratory of Pesticide and Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, PR China.
Photochem Photobiol Sci. 2008 Jun;7(6):694-9. doi: 10.1039/b718761k. Epub 2008 Mar 25.
A simple identification method of L-tyrosine (Tyr) and L-cysteine (Cys) using gemini surfactant coated CdSe quantum dots by using a fluorescent spectroscopic technique is proposed. The gemini surfactant modified QDs show a selective fluorescence response between Tyr and Cys by addition of p-sulfonatocalix[4]arene (pSCA). The CdSe QDs coated with gemini surfactant [C(12)H(25)N(+)(CH(3))(2)(CH(2))(4)(CH(3))(2)N(+)C(12)H(25)].2Br(-) (GS) obviously responds to Tyr. While in the presence of pSCA, it shows selectivity to Cys due to the cooperation of gemini surfactant coated QDs (GS-QDs) and pSCA. Under optimal conditions, it is found that the luminescence of the GS-QDs enhanced by Tyr in a concentration-dependent fashion is described by a Langmuir binding isotherm equation in the range 5 x 10(-8)-10(-5) M. In the presence of pSCA, the luminescence of the GS-QDs enhanced by Cys in a concentration-dependent fashion can also be described by a Langmuir binding isotherm equation in the range 10(-8)-10(-4) M. The possible mechanism is discussed.
提出了一种利用荧光光谱技术，采用双子表面活性剂包覆的CdSe量子点对L-酪氨酸（Tyr）和L-半胱氨酸（Cys）进行简单鉴定的方法。通过添加对磺基杯[4]芳烃（pSCA），双子表面活性剂修饰的量子点在Tyr和Cys之间表现出选择性荧光响应。包覆有双子表面活性剂[C(12)H(25)N(+)(CH(3))(2)(CH(2))(4)(CH(3))(2)N(+)C(12)H(25)].2Br(-)（GS）的CdSe量子点对Tyr有明显响应。而在pSCA存在的情况下，由于双子表面活性剂包覆的量子点（GS-QDs）与pSCA的协同作用，它对Cys表现出选择性。在最佳条件下，发现在5×10(-8)-10(-5) M范围内，Tyr使GS-QDs的发光以浓度依赖方式增强，可用Langmuir结合等温线方程描述。在pSCA存在的情况下，Cys使GS-QDs的发光以浓度依赖方式增强，在10(-8)-10(-4) M范围内也可用Langmuir结合等温线方程描述。并讨论了可能的机理。
