Sensor Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Phys Chem Chem Phys. 2012 Aug 7;14(29):10132-9. doi: 10.1039/c2cp41419h. Epub 2012 Jun 26.
A gold nanoparticle film for surface-enhanced Raman scattering (SERS) was successfully constructed by an ionic surfactant-mediated Langmuir-Blodgett (LB) method. The gold film was formed by adding ethanol to a gold colloid/hexane mixture in the presence of dodecyltrimethylammonium bromide (DTAB). Consequently, gold nanoparticles (AuNPs) assembled at the water/hexane interface due to the decrease in surface charge density of AuNPs. Since DTAB binds the gold surface by a coulombic force, rather than a chemical bonding, it is easily replaced by target molecules for SERS purposes. The SERS enhancement factor of the 80 nm gold nanoparticle film was approximately 1.2 × 10(6) using crystal violet (CV) as a Raman dye. The SERS signal from the proposed DTAB-mediated film was approximately 10 times higher than that from the octanethiol-modified gold film, while the reproducibility and stability of this film compared to an octanethiol-modified film were similar. This method can also be applied to other metal nanostructures to fabricate metal films for use as a sensitive SERS substrate with a higher enhancement factor.
通过离子型表面活性剂介导的 Langmuir-Blodgett（LB）方法成功构建了用于表面增强拉曼散射（SERS）的金纳米粒子薄膜。通过在存在十二烷基三甲基溴化铵（DTAB）的情况下向金胶体/己烷混合物中添加乙醇来形成金膜。因此，由于 AuNPs 的表面电荷密度降低，AuNPs 在水/己烷界面处组装。由于 DTAB 通过库仑力而不是化学键结合到金表面，因此它很容易被用于 SERS 目的的目标分子所取代。使用结晶紫（CV）作为拉曼染料，80nm 金纳米粒子薄膜的 SERS 增强因子约为 1.2×10(6)。与巯基辛烷修饰的金膜相比，所提出的 DTAB 介导的薄膜的 SERS 信号约高 10 倍，而与巯基辛烷修饰的薄膜相比，该薄膜的重现性和稳定性相似。该方法还可应用于其他金属纳米结构，以制造用于作为具有更高增强因子的灵敏 SERS 基底的金属薄膜。
