基于金-银纳米异质二聚体的双酚A的表面增强拉曼光谱检测方法

Surface Enhanced Raman Spectroscopy Based Approach for Detection of Bisphenol A Using Heterogeneous Au-Ag Dimer Nanostructures

构建了一种基于金-银纳米异质二聚体的表面增强拉曼光谱（SERS）检测新方法,实现对双酚A（BPA）的快速、高灵敏传感检测。以DNA分子为模板定向制备高产率的、内嵌有BPA核酸适配体序列的金-银纳米异质二聚体,利用二聚体对其表面拉曼活性分子的增强作用,从而获得强烈的SERS信号。当体系中存在BPA时,会与金纳米颗粒表面修饰的核酸适配体特异性识别,使得金-银异质二聚体解离,体系的SERS信号减弱。利用BPA的浓度与SERS信号强度的变化关系建立标准曲线,达到快速定量检测的目的。结果表明：构建的SERS方法可在30min内实现BPA的高灵敏、高特异性检测。在优化条件下,方法线性范围为0.05-10μg/L,检测限为0.038μg/L。通过实际样品的加入回收实验,证明该方法具有很好的实际应用价值。

In this paper,a surface enhanced Raman spectroscopy（SERS）-based determination method using self- assembled heterogeneous Au-Ag dimers, and its application in rapid and highly sensitive detection of Bisphenol A （BPA） was developed. Firstly, heterogeneous Au-Ag nanoparticles dimers were self-assembled in high yields based on DNA-templated hybridization, in which a BPA specific aptamer sequence was embedded. This nanostructure can exhibit strong SERS signals due to the ＂hotspot＂ regions formed between two nanoparticles （NPs） ,which can amplify the signal of Raman reporter located in the gap region. In the presence of BPA,it can band with DNA aptamer modified on the surface of Au NPs,leading to the dissociation of heterogeneous Au-Ag dimers and the decrease in SERS signals. Based on the relationship of the concentration of BPA and the intensity of SERS signals,rapid and quantitative detection can be achieved. The results showed that BPA can be highly sensitively and selectively detected within 30 min using this method; Under optimal conditions, the limit of detection（LOD） was 0. 038μg/L,the linear range was 0.05μg/L to 10 μg/L. This method can be used for real sample detection,demonstrating a great practical potential.