Electrochemically Deposited Nanoarchitectured Nanoporous Metal Film Using Block Copolymer Micelle for Ultra-Sensitive SERS Platform

Utilizing surface-enhanced Raman scattering (SERS) substrates with plasmonic metals is a rapid, convenient, and powerful spectroscopic technique for molecule detection. The performance of SERS, including the limit of detection (LOD) and enhancement factor (EF), relies on the SERS substrate. These substrates contain plasmonic nanostructures, and the formation of nanogaps between them is one of the crucial factors. Therefore, the development of nanomaterials and nanostructures plays a pivotal role in creating high-performance SERS substrates. Despite numerous studies, achieving rich nanogap formation and establishing reliable processes remain challenging tasks. Firstly, we introduce a novel nanoarchitecture technique utilizing nanoporous metal films and nanoparticles to create abundant nanogaps. We fabricated a new type of SERS substrate with plasmonic nanoporous Au films using a soft-templating method combined with electrochemical deposition. Through precise surface modification and control of surface charge, we achieved well-defined nanogaps. Additionally, we present a new nanoarchitecture technique for forming hotspots by adjusting the gaps between nanoporous plasmonic Au pattern films. By adjusting the deposition voltage and time, we controlled the gaps between the patterns. The nanopatterns and nanoporous structures exhibit strong light trapping ability, owing to multiple reflections of light in the pore, and they possess a larger specific surface area, which enhances the enrichment of target molecules, leading to the formation of more "hot spots" and the enhancement of LSPR effect. Moreover, the multiple electric field couplings of the nanopatterns and nanoporous structures further enhance the local electromagnetic field. In conclusion, 3D SERS sensors hold great potential for revolutionizing various fields such as environmental monitoring, medical diagnostics, and chemical analysis. These products feature ultra-high sensitivity, high spatial resolution, and customizable design, making them indispensable tools for detecting and analyzing molecules at low concentrations. The advancements in substrate fabrication bring us one step closer to maximizing their potential, and continuous research and development will undoubtedly transform approaches to molecular analysis. This presentation emphasizes the importance of utilizing reliable nanomaterials and nanoarchitecture techniques for nanogap formation. Figure 1