SERS Substrate with Integrated Filtering for Nanowire Aggregation

The patent combines multiple functions into a single substrate structure: the substrate serves as both the filtering medium and the support for nanowire aggregation. The filtering layer and nanowire aggregation layer are merged into one integrated structure, eliminating the need for separate filtering and SERS active layers, thus reducing overall device complexity while maintaining enhanced Raman detection capabilities

The substrate acts as an intermediary between the solution containing metal-containing nanowires and the final SERS substrate. By filtering the solution through the substrate, the nanowires are automatically aggregated on the substrate surface in a controlled manner, forming nanogaps without requiring complex alignment or positioning mechanisms. This intermediary filtering process simplifies the fabrication while achieving the desired nanogap structure for surface plasmon resonance

The substrate provides locally optimized conditions for nanowire aggregation through its pore structure and surface properties. Different regions of the substrate can have controlled pore sizes and distributions, creating local zones that guide nanowire aggregation patterns. This local quality control ensures uniform nanowire distribution and consistent nanogap formation across the substrate surface, even while using a simple filtering-based fabrication process

The patent controls the aggregation process by adjusting parameters of the filtering method, such as pore size distribution, flow rate, and nanowire concentration in the solution. By optimizing these parameters, uniform nanowire distribution and consistent nanogap dimensions are achieved. The filtering process parameters can be tuned to control the density and spatial arrangement of nanowires, ensuring manufacturing precision without complicating the overall fabrication approach