一种中空金/银双金属纳米颗粒的制备及其SERS性能

Fabrication of Ag/Au Hollow Bimetallic Nanoparticles and Their SERS Property

以银纳米颗粒为牺牲模板,利用Ag和HAu Cl4之间的置换反应,结合柠檬酸钠同步还原的方法制备了一种中空金/银双金属纳米颗粒。通过对颗粒形貌及局域表面等离子体共振(LSPR)的分析,初步研究了此类金/银纳米颗粒的生长机理,并对影响反应的因素进行了探讨。结果表明,通过控制反应条件可以实现对LSPR的精密调控。该类金/银双金属纳米颗粒可用作为SERS基底,苯硫酚在其表面增强因子可达107,并具有良好的信号重现性。该基底用于atto610标记的生物素与亲和素的SERS检测,检测限可达80 pg/m L。

A novel strategy based on the galvanic replacement reaction(between Ag and HAuCl4)and the coreduction of Ag^+(by sodium citrate)was proposed for the formation of Au/Ag hollow nanoparticles.In the process of synthesis,silver nanoparticles were used as sacrificial templates.The growth mechanism of such Au/Ag hollow nanoparticles was preliminarily investigated by analyzing their morphology and localized surface plasmon resonance(LSPR).The effects of the pipetting mode,the reaction temperature and the amount of reducing agent on the reaction were also discussed.The result shows that,by controlling the proper reaction condition,the SPR of Au/Ag nanoparticles from visible to near infrared region can be precisely modulated.Surface-enhanced Raman scattering(SERS)spectra of thiophenol on Au/Ag nanoparticle substrate were measured,and the enhancement factors could be as high as the value of 10^7.In addition to the significant SERS activity,signals were found excellent repeatability on this Au/Ag nanoparticle substrate.The substrate was further used for the SERS detection of avidin through the recognition between avidin and atto610 labeled biotin.Avidin could be detected over a wide concentration range and the detection limit was 80 pg/mL.