金纳米粒子表面能量转移法测定水中的铅离子

摘要

We established a sensitive method for the detection of lead ions in aqueous solution based on the surface energy transfer between gold nanoparticles and fluorescent dyes. The fluorescein-modified thrombin aptamer (5′-FAM-GGT TGG TGT GGT TGG-3′) can be selectively transformed to G-quadruplex induced by lead ions. The conformation changes of the aptamer can alter the distance between the energy donor of fluorescent dyes and the energy receptor of gold nanoparticles, and further enhance the fluorescence intensity. The fluorescence recovery efficiency ( F/F0 ) is proportional to the concentration of lead ions in the range of 12. 5-100 nmol/L following the linear regression equation of y=0. 910﹢0. 007c(R2=0. 997)and the limit of determination is about 10 nmol/L. The proposed method has been applied to the determination of lead ions in tap water with satisfied results.%荧光素修饰的凝血酶适配体(5′-FAM-GGT TGG TGT GGT TGG-3′)可与Pb2﹢选择性地形成G-四链体，这一构象变化能改变作为能量供体的荧光染料和作为能量受体的金纳米粒子之间的距离，使体系的荧光强度与Pb2﹢浓度具有一定的相关性，从而建立了一种基于纳米材料表面能量转移灵敏检测水溶液中Pb2﹢的分析方法。研究表明，在Pb2﹢浓度为12.5~100 nmol/L范围内，荧光恢复效率(F/F0)与Pb2﹢浓度间呈良好的线性关系，线性回归方程为y=0.910﹢0.007c(R2=0.997)，检出限为10 nmol/L。用本方法检测自来水中Pb2﹢，结果令人满意。