We report new 3D hybrid plasmonic nanostructures exhibiting highly sensitive SERS-based sensing performance,
utilizing efficient plasmonic light absorption and analyte-enrichment effect. The hybrid plasmonic nanostructures
composed of 3D-stacked Ag NWs and NPs separated by a thin hydrophobic dielectric interlayer. A hydrophobic
polydimethylsiloxane (PDMS) interlayer provides dielectric nanogap between Ag NWs and NPs, and analyte-enrichment
effect due to the inhibition of drop spreading. The 3D hybrid PDMS-interlayered Ag nanostructures showed
hydrophobicity with initial contact angle of 137.6°. Utilizing the analyte-enrichment strategy, the PDMS-interlayered Ag
nanostructures exhibited an enhanced sensitivity of methylene blue molecules by a factor of 10 (limit of detection, LOD
of 1.5 nM), compared to the alumina-separated 3D hybrid Ag nanostructures.