Multi-Effect Enhanced Raman Scattering Based on Au/ZnO Nanorods Structures

Abstract

Surface-enhanced Raman scattering (SERS) was considered a potential spectroscopic technique for applications of molecular detection and has drawn great research interest during the past decade. So far, fabrications of cost-effective SERS substrates with high sensitivity and stability and the corresponding enhanced mechanisms are always among the list of research topics, although great progress has been made. In this work, Au particles were decorated on Si, ZnO film and ZnO nanorod arrays simultaneously by an economical method of ion sputtering, generating three kinds of SERS substrates for R6G detection. The morphology difference of Au particles on different samples and the consequent influence on Raman scattering were studied. The experiment results exhibited that substrates with Au particles decorated on ZnO nanorods had the highest Raman enhancement factor. Furthermore, multi-effect enhanced mechanisms summarized as localized surface plasmon resonance (LSPR) filed coupling, electron transferring induced by LSPR of Au particles and whispering gallery mode (WGM) effect of the ZnO cavity were presented. This work provides a convenient and efficient method of fabricating SERS substrates and indicates that such proper metal/semiconductor composite structures are promising candidates for SERS applications.

Plasmonic Molybdenum Dioxide Ultrathin Nanowire Bundles for Highly Sensitive, Stable, and Reproducible Surface-Enhanced Raman Spectroscopy

“…22−31 Additionally, the localized surface plasmon resonance (LSPR) effect, substrate morphology, and size can be optimized to enhance the Raman scattering effect of SERS substrates. 32,33 Here, we report a MoO 2 ultrathin nanowire bundles SERSactive substrate with a rare strong LSPR effect in the visible region centered at 520 nm. The detection limit of the probe molecule R6G on the MoO 2 ultrathin nanowire bundles is as low as 1 × 10 −11 M, with a Raman EF as high as 2.9 × 10 7 .…”

“…Molybdenum dioxide (MoO 2 ) is a commonly used transition metal oxide due to its high electrical conductivity, high melting point, and chemical stability. These properties make it an attractive material for a variety of applications, including catalysts, sensors, recording materials, electrochemical supercapacitors, Li-ion batteries, and field emission materials. − Additionally, the localized surface plasmon resonance (LSPR) effect, substrate morphology, and size can be optimized to enhance the Raman scattering effect of SERS substrates. , …”

Comparison of Surface-Enhanced Raman Scattering in Colloidal Silver Nanostar ‎and Colloidal Silver Nanocubes

“…SERS is potent fingerprint spectroscopy that can in situ identify the active sites and the surface reaction intermediates during catalytic processes since it can produce surface-sensitive as well as chemical bond-specific signals at the atomic level 7 . By adjusting the colloidal particle sizes, shapes, and compositions, an enhancement factor of up to 14 orders of magnitude has been achieved for SERS substrates 8 . When molecules are adsorbed onto corrugated metal surfaces, such as silver or gold nanoparticles (NPs), the inelastic light scattering by molecules is significantly increased (by factors up to 10 8 or even larger, enabling single-molecule (SM) SERS in some cases), see Fig.…”

Synthesis and Raman Performance Enhancement of Multilayer AuAg Heterostructures with Magnetic Resonance

“…Li et al [35] synthesized a dimer of silver nanospheres without any additional assembly by optimizing the amount of chloride added to polyol synthesis to control the colloid stability and oxidation etching, and then studied the SERS effect of the hot spot of the dimer. Lin et al [36] synthesized a substrate modified with Au particles on ZnO nanorods using ion sputtering method, which had a very high Raman enhancement factor. This structure was expected to become an SERS substrate with high sensitivity and stability.…”