β-环糊精修饰的CdSe量子点荧光开关法测定铝

Determination of aluminum (Ⅲ) by fluorescence switch method based on β-cyclodextrin-modified CdSe sequantum dots

以3-巯基丙酸为稳定剂,合成了水溶性的Cd Se量子点(Cd Se QDs),并用β-环糊精(β-CD)修饰该量子点。依据桑色素存在的条件下,CdSe-β-CD QDs荧光恢复程度与Al^(3+)浓度成正比关系,建立了荧光开关测定Al^(3+)的新方法。探究了桑色素浓度、缓冲溶液及pH、温度、时间等条件对检测体系的影响。在最佳条件下,Al^(3+)在4~60μmol/L范围内与CdSe-β-CD QDs荧光恢复呈良好线性关系,相关系数为0.9942,检出限为69 nmol/L,相对标准偏差为2.0%。方法用于牛奶中Al^(3+)的检测,回收率为96.8%~105.3%。

Hydrophilic β-cyclodextrin-modified CdSe quantum dots （CdSe-β-CD QDs ） were synthesized using 3-mercaptopropionic acid as stabilizer. In the presence of morin, the recovery degree of fluorescence intensity of CdSe-β-CD QDs was proportional to the concentration of Al^3＋. A novel method for the Al^3＋ detection by CdSe-β-CD QDs-based fluorescence switch was established. Different factors were studied, including the morin concentration, buffer solution, pH, reacting time. It was found that the recovery degree of fluorescence intensity of CdSe-β-CD QDs had a good linear relationship to the concentration of Al^3＋ in the range of 4 - 60 μmol / L under the optimal conditions. The detection limit was 69 nmol/L. The correlation coefficient was 0. 9942. The relative standard deviation was 2.0% （ n = 8 ）. The method was applied to the determination of the Al^3＋＋ concentration in milk samples. The recovery was 96. 8% ~ 105.3%.