摘要
以3-巯基丙酸为稳定剂,采用水热法合成了具有优异光学性质的CdTe/CdS核壳型量子点,量子产率为13.8%。量子点与牛血清白蛋白（BSA）偶联后荧光强度明显增大。通过测定荧光强度确定了偶联的最佳反应条件：pH7.4,反应温度37℃,反应时间40min。研究了溶液pH值和NaCl浓度对量子点及量子点-BSA溶液荧光强度的影响。对牛血清白蛋白测定的线性范围为1.1~19.5mg/L;检出限为0.47mg/L。头孢曲松钠对量子点-BSA的荧光有明显猝灭作用,荧光猝灭程度与其浓度有良好的线性关系。实验结果表明为静态猝灭,头孢曲松钠与BSA按1∶1结合,结合常数为6.31×10^3L/mol。用圆二色光谱技术探讨了其对BSA构象的影响。
The CdTe/CdS core/shell quantum dots （QDs） that have special spectral properties were prepared with 3-mercaptopropionic acid as stabilizer by hydrothermal synthesis method, the quantum yield of fluorescence was 13.8%. The results demonstrate that the fluorescence intensity was increased obviously when CdTe/CdS QDs conjugated to the bovine serum albumin （BSA）. The optimum reaction conditions of quantum dots conjugated to the protein were tested by determining the fluorescence intensity of CdTe/CdS QDs-BSA solution （ pH 7.4 ; the reaction time, 40 minute ; the reaction temperature, 37 ℃ ）. The effects of solution pH and NaCl concentration on the fluorescence intensity of CdTe/CdS QDs and CdTe/CdS QDs-BSA solution were discussed. The Calibration graph for BSA determination was linear over the range of 1.1 - 19.5 mg/L with a detection limit of 0.47 mg/L BSA. The results also indicated that the florescence intensity of CdTe/CdS QDs -BSA was quenched by ceftriaxone. The quenching fluorescence intensity is linearly proportional to the concentration of ceftriaxone, and the quenching mechanism of fluorescence is a static quenching procedure. The binding constant （KA） of ceftriaxone to BSA can be estimated to be 6.31 × 10^3 L/mol, with the binding sites of 1. The effect of ceftriaxone on the conformation of BSA has also been analyzed using circular dichroism spectrometry.
出处
《分析化学》
SCIE
CAS
CSCD
北大核心
2008年第4期444-448,共5页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No.20475024)
聊城大学科研基金(No.X061003)资助项目
关键词
量子点
牛血清白蛋白
荧光猝灭
头孢曲松钠
Quantum dots, bovine serum albumin, fluorescence quenching, ceftriaxone
