Plasma-Induced Formation of Ag Nanodots for Ultra-High-Enhancement Surface-Enhanced Raman Scattering Substrates

Abstract

We report here plasma-induced formation of Ag nanostructures for surface-enhanced Raman scattering (SERS) applications. An array of uniform Ag patterned structures of 150 nm diameter was first fabricated on a silicon substrate with imprint lithography; then the substrate was further treated with an oxygen plasma to fracture the patterned structures into clusters of smaller, interconnected, closely packed Ag nanoparticles (20-60 nm) and redeposited Ag nanodots ( approximately 10 nm) between the clusters. The substrate thus formed had a uniform ultrahigh SERS enhancement factor (1010) over the entire substrate for 4-mercaptophenol molecules. By comparison, Au patterned structures fabricated with the same method did not undergo such a morphological change after the plasma treatment and showed no enhancement of Raman scattering.

Surface‐enhanced Raman scattering from gold‐coated germanium oxide nanowires

“…18 This scale of controlled separation is still beyond the resolution of any scalable top-down fabrication approach. 19 Common SERS substrates fabricated using noble metal colloidal, electrochemically roughened thin films, and cold deposited metal films suffer from lack of homogeneity, where only a few hot spots yield high enhancement. This work is motivated by the desire to fabricate an economical, stable, and uniform SERS substrate that can be used to detect trace amount of chemicals and biospecies.…”

Fabrication of nano-indented cavities on Au for the detection of chemically-adsorbed DTNB molecular probes through SERS effect

“…In Table 1, the highest enhanced I peak (2) for nAu samples #1-6 was recorded as the specific band and used as the reference value for I SERS . For NTB molecules ideally adsorbed and forming a well-ordered monolayer on the nAu, the ideal value of average N SERS is %10 5 molecules/lm 2 [41].…”

Fabrication and optical properties of size-controlled Ag nanodot array via nanoporous alumina mask

“…The characteristic of LSPR depends on the composition, size, array structure, and shape of silver nanostructures and the dielectric environment [4,5]. Ag nanostructures have been formed by various lithographic techniques [5,6]. Ag nanostructure has led to many important applications pertaining to a sensor.…”