基于牛血清白蛋白功能化金纳米棒的荧光探针测定Hg^(2+)

Fluorescent Probe for Hg^(2+)Detection Based on Functionalized Gold Nanorods

建立了一种以牛血清白蛋白功能化的金纳米棒(BSA-Cys-GNRs)为荧光探针检测Hg^(2+)的新方法。以半胱氨酸作为连接臂成功将牛血清白蛋白修饰在金纳米棒表面,通过紫外可见吸收光谱、荧光光谱、红外光谱和荧光倒置显微镜等多种分析方法对材料进行表征。研究发现,在295nm波长光激发下,BSA-Cys-GNRs探针在338nm显示强荧光,而Hg^(2+)能够有效地猝灭BSA-Cys-GNRs的荧光。对一系列影响猝灭效果的因素进行考察,得出pH 4.0、孵育时间5.0min为最佳检测条件。Mn^(2+)、K^(+)、Ni^(2+)、Na^(+)、Cr^(3+)、Cd^(2+)、Mg^(2+)、Cu^(2+)、Ca^(2+)、Al^(3+)和Zn^(2+)对BSA-Cys-GNRs的荧光信号没有明显的影响。当Hg^(2+)的浓度为0.04444~8.888μmol·L^(-1)时,荧光猝灭效率与Hg^(2+)的浓度之间存在良好的线性关系,检测限为8.08nmol·L^(-1)。将该方法用于环境水样中Hg^(2+)的检测,回收率为98.9%~105.0%。

Bovine serum albumin(BSA)functionalized gold nanorods(BSA-Cys-GNRs)as a fluorescence probe for the detection of Hg^(2+)has been developed in this work.BSA was successfully modified on the surface of gold nanorods with cysteine as the linker.The materials were characterized by UV-Vis,FL,FT-IR and inverted fluorescence microscopy.The BSA-Cys-GNRs displays strong fluorescence emission peak at 338 nm under excitation at 295 nm.The fluorescence of BSA-Cys-GNRs is strongly quenched upon addition of Hg^(2+)ions.Effective detection conditions are pH 4.0 and incubating time 5.0 min.Mn^(2+),K^(+),Ni^(2+),Na^(+),Cr^(3+),Cd^(2+),Mg^(2+),Cu^(2+),Ca^(2+),Al^(3+)and Zn^(2+)are examined under identical conditions,and all of them do not induce any noticeable responses to BSA-Cys-GNRs.There is a good linear dependence of fluorescence intensity on Hg^(2+)concentration in the range of 0.04444~8.888μmol·L^(-1)with the detection limit of 8.08 nmol·L^(-1).Furthermore,the method has been applied for the determination of Hg^(2+)in water samples,and the recoveries are in the range of 98.9%~105.0%.