Gold-rich ligament nanostructure by dealloying Au-based metallic glass ribbon for surface-enhanced Raman scattering

Abstract

A new method to fabricate an Au-rich interconnected ligament substrate by dealloying the Au-based metallic glass ribbon for surface-enhanced Raman scattering (SERS) applications was investigated in this study. Specifically, three substrates, Au film, Au-based metallic glass ribbon, and dealloyed Au-based metallic glass ribbon, were studied. The dealloyed surface showed ligament nanostructure with protruding micro-islands. Based on the field emission scanning electron microscopy, reflection and scattering measurements, the dealloyed Au-based metallic glass provided a large surface area, multiple reflections, and numerous fine interstices to produce hot spots for SERS enhancements. The SERS signal of analyte, p-aminothiophenol, in the micro-island region of dealloyed Au-based metallic glass was about 2 orders of magnitude larger than the flat Au film. Our work provides a new method to fabricate the inexpensive and high SERS enhancements substrates.

Structural and Optical Properties of Textured Silicon Substrates by Three-Step Chemical Etching

“…Compared to the flat Si substrate, the textured Si substrates had much stronger Raman signals, and the Raman intensity increased with the increasing p-ATP concentration for the same textured Si substrate. 49 Among the three textured samples, sample 50 + 60 + 1 had the highest Raman intensity, and sample 50 had the lowest Raman intensity for the same p-ATP concentration, indicating the Raman signal enhancements of the second-step and the third-step etching. 43,50,51 Compared to the flat-silicon substrate, the samples 50 + 60 + 1, 50 + 60, and 50 also exhibited Raman signal enhancements (Figure 11a).…”

Chemically Etched Nanoporous Copper and Galvanically Displaced Silver Nanoflowers for SERS Sensing

“…Dealloying is a vintage chemical method that finds interest in creating nanoporous metals, and a few studies have established their application to SERS. 31,32 However, further enhancing the SERS activity of these nanoporous metals through the galvanic displacement is less explored. One such example is the nanoporous Cu (NPC) preparation by the selective dealloying of a melt-spun Cu 30 Mn 70 alloy ribbon.…”

“…Some notable examples include the use of transmission electron microscopy (TEM) Cu microgrids, microcontact printed Cu micropatterns, and silicon nanowires or pyramidal arrays prepared via chemical etching. Dealloying is a vintage chemical method that finds interest in creating nanoporous metals, and a few studies have established their application to SERS. , However, further enhancing the SERS activity of these nanoporous metals through the galvanic displacement is less explored. One such example is the nanoporous Cu (NPC) preparation by the selective dealloying of a melt-spun Cu 30 Mn 70 alloy ribbon.…”

Photochemical Synthesis of Porous CuFeSe2/Au Heterostructured Nanospheres as SERS Sensor for Ultrasensitive Detection of Lung Cancer Cells and Their Biomarkers

“…Recently, Au nanostructures are attractive SERS substrates due to its unique thermal, optical, and electronic properties. − Generally, the morphology of gold has a significant impact on its SERS activity. , For example, the latest research shows that nanostructured Au with a rich “hot spot” is beneficial for SERS. − Moreover, with very high enhancement factors obtained from the hot spots between the dimer and the trimer of a nanoparticle and the edge/corner of nanoparticles (NPs), more and more efforts have been focused on establishment of dealloyed nanoporous metals to improve signal stability, reproducibility, and practical operation. − Such unique characteristics are not only beneficial to the excitation of the local surface plasma but also offer a great deal of molecular binding sites. However, when these nanoporous metals are used as substrates to detect single molecules, the SERS signal is either poorly repeatable or inadequate.…”