有序Au/Ag纳米碗阵列的简易制备及其表面增强拉曼散射性能

通过湿法化学合成基于SiO₂胶体晶体的大面积有序Au/Ag纳米碗(Au/AgNB)阵列。首先，在玻璃基板上组装3D SiO₂胶体晶体作为模板。然后，以Au纳米颗粒(AuNP)为种子，通过原位生长法在SiO₂模板上沉积一层Au纳米壳(AuNS)。再通过HCHO还原Ag⁺成Ag⁰，进一步在AuNS表面沉积Ag纳米壳，形成Ag/Au双纳米壳(Ag/AuNS)阵列。最后通过丙烯酸酯改性双向取向聚丙烯(BOPP)膜方便地获得了单层有序反转Ag/AuNB阵列。这种有序Au/AgNB阵列具有更佳的表面增强拉曼散射(SERS)活性，其SERS分析增强因子(AEF)可达2.23×10⁷。

Facile fabrication and surface-enhanced Raman scattering properties of ordered Au/Ag nanobowl array

Herein,we present a novel and simple method to fabricate a large-area ordered Au/Ag nanobowl (Au/AgNB) array based on SiO₂ colloidal crystals by wet chemosynthesis.The arrays combine the advantages of gold and silver and have been well recognized as excellent surface-enhanced Raman scattering (SERS) substrates in practical application.First of all,a 3D SiO₂ colloidal crystal was arrayed on the glass substrate as a template.Then,a layer of Au nanoshell (AuNS) was deposited on the 3D SiO₂ template by in-situ growth method with the help of Au nanoparticle (AuNP) seeds.Afterward,silver nanoshells were further deposited on the surface of AuNS by HCHO-reduced Ag⁺,then Ag/Au double nanoshell (Ag/AuNS) array was formed.A monolayer-ordered reversed Ag/AuNB array was conveniently obtained by an acrylic ester-modified biaxial-oriented polypropylene (BOPP).The ordered Au/AgNB array with adjustable periodic holes,shapes,and sizes could be obtained when the SiO₂ core was etched by HF solution.With prominent stability and reproducibility,the SERS analytical enhancement factor (AEF) of this ordered Au/AgNB array could reach 2.23×10⁷,which shows high SERS enhancing activity and can be used as a universal SERS substrate.