Using Si/MoS2 Core-Shell Nanopillar Arrays Enhances SERS Signal

Abstract

Two-dimensional layered material Molybdenum disulfide (MoS2) exhibits a flat surface without dangling bonds and is expected to be a suitable surface-enhanced Raman scattering (SERS) substrate for the detection of organic molecules. However, further fabrication of nanostructures for enhancement of SERS is necessary because of the low detection efficiency of MoS2. In this paper, period-distribution Si/MoS2 core/shell nanopillar (NP) arrays were fabricated for SERS. The MoS2 thin films were formed on the surface of Si NPs by sulfurizing the MoO3 thin films coated on the Si NP arrays. Scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy were performed to characterize Si/MoS2 core-shell nanostructure. In comparison with a bare Si substrate and MoS2 thin film, the use of Si/MoS2 core-shell NP arrays as SERS substrates enhances the intensity of each SERS signal peak for Rhodamine 6G (R6G) molecules, and especially exhibits about 75-fold and 7-fold enhancements in the 1361 cm−1 peak signal, respectively. We suggest that the Si/MoS2 core-shell NP arrays with larger area could absorb more R6G molecules and provide larger interfaces between MoS2 and R6G molecules, leading to higher opportunity of charge transfer process and exciton transitions. Therefore, the Si/MoS2 core/shell NP arrays could effectively enhance SERS signal and serve as excellent SERS substrates in biomedical detection.

Hybrid Enhancement of Surface-Enhanced Raman Scattering Using Few-Layer MoS2 Decorated with Au Nanoparticles on Si Nanosquare Holes

“…In this study, all MoS 2 structures were obtained in a furnace by sulfurizing MoO 3 thin films coated on various substrates. The MoO 3 method and subsequent sulfurization for MoS 2 growth were reported in our previous study [ 21 ]. We maintained the same parameters in this study, except for decreasing the deposition time of MoO 3 to 5 s to obtain a few-layer MoS 2 structure.…”

Plasma‐Etched Nanograss Surface without Lithographic Patterning to Immobilize Water Droplet for Highly Sensitive Raman Sensing

“…However, trapping target molecules close to the plasmonic hot spots generated by nanostructures prolongs the accumulation time required to detect molecules in dilute solutions. [ 6 ] To address this limitation, several methods for enhancing the effectiveness of the interactions between molecules and hot spots have been developed by designing nanostructures, such as nanospheres, [ 7 ] nanogaps, [ 8 ] nanopores, [ 9 ] nanopillars, [ 10 − 12 ] and nanotubes. [ 13 ] Furthermore, several advanced techniques including tip‐enhanced Raman scattering, [ 14 ] shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS), [ 15 ] and liquid interface‐assisted SERS (LI‐SERS) have been employed in SERS.…”

Nanomaterials and Nanostructures Hand-In-Hand with Biology

“…The great advantages of SERS mean that thousands of articles are published every year using this technique for different purposes. Focusing on this Special Issue, the authors used silicon nanopillars coated with molybdenum disulfide (MoS 2 ) as SERS substrates [ 8 ]. The preparation of these substrates is done by thermal growth using a mask, allowing Si cylinders to grow perpendicular to the surface.…”