Sensitive and uniform detection using Surface-Enhanced Raman Scattering: Influence of colloidal-droplets evaporation based on Au-Ag alloy nanourchins

Dongjie Zhang; Jixiang Fang; Tao Li

doi:10.1016/j.jcis.2017.12.017

Sensitive and uniform detection using Surface-Enhanced Raman Scattering: Influence of colloidal-droplets evaporation based on Au-Ag alloy nanourchins

J Colloid Interface Sci. 2018 Mar 15:514:217-226. doi: 10.1016/j.jcis.2017.12.017. Epub 2017 Dec 6.

Authors

Dongjie Zhang¹, Jixiang Fang², Tao Li³

Affiliations

¹ Key Laboratory of Physical Electronics and Devices of Ministry of Education, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
² Key Laboratory of Physical Electronics and Devices of Ministry of Education, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China. Electronic address: jxfang@mail.xjtu.edu.cn.
³ Shaanxi Institute for Food and Drug Control, Xi'an, Shaanxi 710065, China. Electronic address: westyx@126.com.

PMID: 29268212
DOI: 10.1016/j.jcis.2017.12.017

Abstract

Surface Enhanced Raman Scattering (SERS) has been developed into a powerful vibrational spectroscopy technique for chemical detection. However, the fabrication of colloidal droplets-based SERS substrates with well reproducibility and uniformity still remains challenging. In this paper, colloidal suspensions of hollow Au-Ag alloy nanourchins (HAAA-NUs) and Au nanoparticles (Au NPs) with different morphologies were employed as SERS-active substrates. After evaporation of colloidal suspensions, we evaluated the SERS performance based on the following features: "Coffee Ring Effects", adsorption processes of probe molecule and colloidal NPs, spin coating and morphologies of suspended NPs. The results demonstrated that SERS signals could be enhanced enormously in the marginal region of Coffee Ring patterns. The limit of detection (LOD) for amaranth molecule would be reached 10^-8 M. Moreover, by combining the droplets evaporation of HAAA-NUs suspensions with spin coating, the relative standard deviation (RSD) could be down to 3.5%, showing excellent reproducibility. The investigation here would provide a simple, practical and portable SERS detection method with excellent signal uniformity.

Keywords: Adsorption process; Au-Ag alloy nanourchins; SERS; “Coffee Ring Effects”.