Although surface-enhanced Raman spectroscopy (SERS) enables highly sensitive molecular detection, traditional substrates generally suffer from limited spectral tunability of localized surface plasmon resonances (LSPRs). Here we develop a gold-coated inverse opal photonic–plasmonic nanostructure, where Bragg modes alter the spectral position of the plasmonic resonance, forming tunable platforms for SERS. We introduce a dynamic tuning strategy leveraging the continuous shifting of the hybrid photonic-plasmonic resonance by varying the incident angle, eliminating the need to fabricate new structures. The hybrid resonance is adjusted to the optimal position relative to the chosen excitation wavelength, which is strategically selected to maximize the target molecules SERS response. The fabricated nanostructure exhibits a SERS enhancement factor of 2.75 × 106 for Rhodamine 6G at normal incidence. Our proposed SERS optimization demonstrates a 7.7-fold signal increase and improves the limit-of-detection by an order-of-magnitude. Such hybrid photonic–plasmonic platform enables continuous SERS amplification without modifying substrate geometry and is broadly applicable to chemical sensing and environmental monitoring. Surface-enhanced Raman spectroscopy is highly sensitive, but traditional substrates have limited plasmon resonance tunability. Here, the authors develop a gold-coated inverse opal nanostructure where Bragg modes tune plasmonic resonance, enabling angle-controlled surface-enhanced Raman spectroscopy without new fabrication.
Lin et al. (Sat,) studied this question.