Guided Wrinkling of Hierarchically Structured Nanoporous Gold Films for Improved Surface‐Enhanced Raman Scattering Performance

Abstract

Plasmonic nanostructured metals have many advantages for applications in high-performance surface-enhanced Raman scattering (SERS) spectroscopy. In particular, unique designing nanostructures with bicontinuous ligaments surrounded by cylindrical voids with tunable dense pores from a few to hundreds of nanometers can be utilized for the high-performance SERS-active substrate. Here, a fabrication strategy is reported to prepare hierarchically arranged micro/nanostructures of wrinkled nanoporous gold (WNPG) films, which involves laminating of the dealloyed Au film on the heat-shrinkable shape-memory polymer film and geometrical modulation of the substrate. As a result, the various types of WNPG films are crafted with a remarkable density of cracks in the structured surface area. Specifically, the WNPG films consisting of multilayered overlapping features are explored and used as the SERS-active substrate. This dual porosity coupled with localized surface plasmon resonance estimated by numerical simulation in a suitable model of bicontinuous ligaments is found to be the core mechanism for the enhancement of SERS sensitivity, which quantitatively characterizes the "hot spots" from the surface to interlayers. These suggested characteristic features are fully assessed by applying a series of dye molecules and DNA strands on the prepared SERS substrate, demonstrating the enhanced intensity of the Raman scattering signals on the optimized WNPG surface.

3D Nanoporous Metallic Networks for SERS-Based Detection of Water Contaminants

“…Nanoporous metallic networks represent a fascinating class of materials, exhibiting an intricate architectural structure with high surface area, unlocking a plethora of possibilities in various fields, among them photocatalysis, sensing, nanophotonics, and electrochemistry. ,− …”

Mobile Point-of-Care Device Using Molecularly Imprinted Polymer-Based Chemosensors Targeting Interleukin-1β Biomarker

“…As for in vitro diagnostic (IVD) medical devices, these types of chemosensors with enhanced sensitivity/selectivity and simple operating systems could be the main potential strategy to provide clinicians with valuable information on the condition of the soft-tissue destruction in periodontitis [14]. In this context, versatile approaches for clinical diagnosis methods have been proposed, such as lab-on-chip technology [15,16], lateral-flow assays [17,18], electrochemical electrodes [19,20], surface-enhanced Raman scattering [21][22][23], and integrated semiconducting transistors [24,25]. In view of the biological sensing capability, the creation of recognizable active sites is critically required for the stable physical and chemical interactions in the transducing process to build an advanced POCT system.…”