Fabrication of large-area silica inverse opal composite films with embedded gold nanorods for SERS applications

초록

Surface-enhanced Raman scattering (SERS) is progressively emerging as a highly sensitive analytical technique for detecting biomolecules on the surface of nanoparticles. In this study, we developed a large-area silica (SiO2) inverse opal composite film with embedded gold nanorods (GNRs) for SERS and sensing applications. Simple, rapid, and low-cost techniques employed to synthesize poly(methyl methacrylate) (PMMA) opal films and SiO2 precursors were spin-coating, dip-coating, and evaporation-induced self-assembly, followed by calcination to remove the PMMA template and produce SiO2 inverse opal films. SiO2 inverse opal films with an area of several square centimeters were embedded in GNRs by dropping them to form GNR-embedded SiO2 (GNR-SiO2) inverse opal composite films. The structure, optical properties, and surface morphology of the GNR-SiO2 inverse opal composite films were characterized. The resulting GNR-SiO2 inverse opal composite films exhibited a linear relationship between methylene blue (MB) concentration and Raman signal intensity within the nanomolar concentration range, enabling the construction of a reliable standard curve for MB detection. Additionally, the films exhibited a significant increase in SERS signal compared to the conventional GNR assembly. Therefore, GNR-SiO2 inverse opal composite films are a promising material for novel SERS applications.

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