Tunable Silver Nanoparticle Arrays by Hot Embossing and Sputter Deposition for Surface-Enhanced Raman Scattering

Chu-Yu Huang,Ming-Shiuan Tsai

doi:10.3390/app9081636

Abstract

Surface-enhanced Raman scattering (SERS) spectroscopy has attracted a lot of attention over the past 30 years. Due to its extreme sensitivity and label-free detection capability, it has shown great potential in areas such as analytical chemistry, biochemistry, and environmental science. However, the major challenge is to manufacture large-scale highly SERS active substrates with high controllability, good reproducibility, and low cost. In this study, we report a novel method to fabricate uniform silver nanoparticle arrays with tunable particle sizes and interparticle gaps. Using hot embossing and sputtering techniques, we were able to batch produce the silver nanoparticle arrays SERS active substrate with consistent quality and low cost. We showed that the proposed SERS active substrate has good uniformity and high reproducibility. Experimental results show that the SERS enhancement factor is affected by silver nanoparticles size and interparticle gaps. Furthermore, the enhancement factor of the SERS signal obtained from Rhodamine 6G (R6G) probe molecules was as high as 1.12 × 107. Therefore, the developed method is very promising for use in many SERS applications.

Highlights

Surface-enhanced Raman spectroscopy (SERS) technology has attracted widespread attention since its discovery in 1974 [1]
This results in a gap between the nanospheres in the range of a few nanometers and is suitable for generating many intense hot spots, which is very helpful for enhancing the SERS effect
The SERS active substrate was fabricated through hot embossing and sputtering deposition

Summary

Introduction

Surface-enhanced Raman spectroscopy (SERS) technology has attracted widespread attention since its discovery in 1974 [1]. Comparing to the normal Raman scattering process, SERS is capable of enhancing Raman scattering of analytes by up to a million times or more [2]. Used a SERS probe for intracellular imaging, SERS signals were strong enough and could be detected even from inside cells. Many SERS substrates use colloidal clusters of noble metal nanoparticles or noble metals with a rough surface to enhance SERS signals. An [7] et al used silver nanoparticles, tri-iron tetroxide, and carbon cores to form multilayered microsphere particles SERS substrate to detect pentachlorophenol (PCP), diethylhexyl phthalate (DEHP), and trinitrotoluene (TNT). In 2014, Au-Ag-S substrate developed by Cao et al [8] was used for surface-enhanced Raman detection and photocatalytic degradation of DEHP and DEHA. Liu et al [9] developed an alloy of gold and silver

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Results

Conclusion