Enhancing Surface-Enhanced Raman Scattering Intensity through Light Diffuse Reflection on Ag/ZnO Nanowire Arrays

초록

In this study, we present a new strategy to enhance the intensity ofsurface-enhanced Raman scattering (SERS) signals by using three-dimensionalaggregated silver nanoparticles (AgNPs) on the zinc oxide nanowire arrays (Ag/ZnONWA). The ZnO NWA acts as a light-scattering substrate, providing multidirectionalincident light and reflecting a portion of the Raman scattered light, resulting in animproved SERS signal intensity. The composite nanowire structure of the Ag/ZnONWA was successfully fabricated, and 400 nm ZnO nanowires in the Ag/ZnO NWAexhibit optimal diffuse light reflection, resulting in a significant improvement of theSERS signal intensity. The SERS enhancement factor (EF) for the Ag/ZnO NWAwas determined to be EF (ISERS/NSERS)/(IRaman/NRaman) = 3.5 × 106. This substrategenerated a ∼7.9-fold increased SERS signal compared to the preaggregated AgNPsin the absence of the ZnO NWA. The detection limit of the Ag/ZnO NWA wasestimated by measuring SERS spectra of rhodamine B, enabling discrimination downto 10−15 M. Our approach inducing multidirectional diffuse reflection light to SERShot spots provides a simple and efficient strategy to enhance SERS signal intensity, with broad implications for other spectroscopicapplications

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