Cha Myeong Geun, Kim Hyung-Mo, Kang Yoo-Lee, Lee Minwoo, Kang Homan, Kim Jaehi, Pham Xuan-Hung, Kim Tae Han, Hahm Eunil, Lee Yoon-Sik, Jeong Dae Hong, Jun Bong-Hyun
Department of Chemistry Education, Seoul National University, Seoul, Republic of Korea.
Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea.
PLoS One. 2017 Jun 1;12(6):e0178651. doi: 10.1371/journal.pone.0178651. eCollection 2017.
Surface-enhanced Raman scattering (SERS) provides a unique non-destructive spectroscopic fingerprint for chemical detection. However, intrinsic differences in affinity of analyte molecules to metal surface hinder SERS as a universal quantitative detection tool for various analyte molecules simultaneously. This must be overcome while keeping close proximity of analyte molecules to the metal surface. Moreover, assembled metal nanoparticles (NPs) structures might be beneficial for sensitive and reliable detection of chemicals than single NP structures. For this purpose, here we introduce thin silica-coated and assembled Ag NPs (SiO2@Ag@SiO2 NPs) for simultaneous and quantitative detection of chemicals that have different intrinsic affinities to silver metal. These SiO2@Ag@SiO2 NPs could detect each SERS peak of aniline or 4-aminothiophenol (4-ATP) from the mixture with limits of detection (LOD) of 93 ppm and 54 ppb, respectively. E-field distribution based on interparticle distance was simulated using discrete dipole approximation (DDA) calculation to gain insight into enhanced scattering of these thin silica coated Ag NP assemblies. These NPs were successfully applied to detect aniline in river water and tap water. Results suggest that SiO2@Ag@SiO2 NP-based SERS detection systems can be used as a simple and universal detection tool for environment pollutants and food safety.
表面增强拉曼散射（SERS）为化学检测提供了独特的非破坏性光谱指纹。然而，分析物分子与金属表面亲和力的内在差异阻碍了SERS作为同时检测各种分析物分子的通用定量检测工具。在保持分析物分子与金属表面紧密接近的同时，必须克服这一问题。此外，与单个纳米颗粒（NP）结构相比，组装的金属纳米颗粒结构可能有利于对化学物质进行灵敏且可靠的检测。为此，我们在此引入薄二氧化硅包覆且组装的银纳米颗粒（SiO2@Ag@SiO2 NPs），用于同时定量检测对银金属具有不同固有亲和力的化学物质。这些SiO2@Ag@SiO2 NPs能够分别从混合物中检测出苯胺或4-氨基苯硫酚（4-ATP）的每个SERS峰，检测限（LOD）分别为93 ppm和54 ppb。利用离散偶极近似（DDA）计算模拟了基于颗粒间距离的电场分布，以深入了解这些薄二氧化硅包覆的银纳米颗粒组装体增强散射的情况。这些纳米颗粒已成功应用于检测河水和自来水中的苯胺。结果表明，基于SiO2@Ag@SiO2 NPs的SERS检测系统可作为一种简单通用的检测工具，用于环境污染物检测和食品安全检测。
