基于金银合金纳米线SERS活性基底的制备

Preparation of Surface-Enhanced Raman Scattering Active Substrates Based on Au-Ag Alloy Nanowires

首先采用液相软模板方法合成银纳米线,然后采用静电吸附法将带负电荷的银纳米线和带正电荷的金纳米颗粒组装形成金银合金纳米线。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线能谱分析仪(EDS)对材料的形貌和成分进行表征,结果表明金纳米颗粒被均匀吸附在银纳米线的表面。之后将金银合金纳米线偶联到氨基化处理后的硅片抛光面上,组装得到均匀、致密排列的金银合金纳米线表面增强喇曼散射(SERS)基底,该基底具有良好的重现性、均一性和SERS活性。使用尼罗蓝A (NBA)作为喇曼信号分子,SERS基底的最低检测浓度为7.93×10^-10mol/L,其分析增强因子(AEF)为6.31×10^7,SERS增强效应很高。此外金银合金纳米线具有高稳定性和良好的生物相容性,因此该基底在SERS生物传感方面具有广阔的应用前景。

Firstly,silver nanowires were synthesized by liquid-phase soft-film plate method,and then the negatively charged silver nanowires and positively charged gold nanoparticles were assembled to form Au-Ag alloy nanowires(Au-Ag NWs)by electrostatic adsorption method.The morphology and composition of the material were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray energy dispersive spectrometry(EDS).The result shows that the gold nanoparticles are evenly adsorbed on the surface of silver nanowires.Finally,the Au-Ag NWs were coupled to the polished surface of the aminated silicon wafer to prepare a uniform and compact surface-enhanced Raman scattering(SERS)substrate with good reproducibility,uniformity and SERS activity.Using Nile blue A(NBA)as Raman signal molecule,the lowest detection concentration and the analytical enhancement factor(AEF)of the SERS substrate is 7.93×10^-10mol/L and 6.31×10^7,respectively.The SERS enhancement effect is great.Besides,the Au-Ag NWs have high stability and good biocompatibility,and the substrate has great application prospects in SERS biosensors.