Highly effective and chemically stable surface enhanced Raman scattering substrates with flower-like 3D Ag-Au hetero-nanostructures

Abstract

We demonstrated flower-like 3D Ag-Au hetero-nanostructures on an indium tin oxide glass (ITO glass) for surface enhanced Raman scattering (SERS) applications. The flower-like 3D Ag nanostructures were obtained through electrodeposition with liquid crystalline soft template which is simple, controllable and cost effective. The flower-like 3D Ag-Au hetero-nanostructures were further fabricated by galvanic replacement reaction of gold (III) chloride trihydrate (HAuCl4·3H2O) solution and flower-like Ag. The flower-like Ag-Au hetero-nanostructure exhibited stronger SERS effects and better chemical stability compared with flower-like Ag nanostructure. The localized surface plasmon resonance (LSPR) spectra, field emission scanning electron microscope (FESEM) photos and Ag-Au ratios were studied which show that the surface morphology and shape of the flower-like Ag-Au hetero-nanostructure play significant roles in enhancing SERS. The flower-like 3D Ag-Au hetero-nanostructures fabricated by electrodeposition in liquid crystalline template and galvanic replacement reaction are simple, cheap, controllable and chemical stable. It is a good candidate for applications in SERS detection and imaging.

Improved SERS Performance and Catalytic Activity of Dendritic Au/Ag Bimetallic Nanostructures Based on Ag Dendrites

“…We assumed that the 1,4-BDT molecules were uniformly dispersed on the substrate and that all the molecules within the laser spot were illuminated and contributed to the SERS and Raman spectra. Under the excitation at 488 nm, the SERS enhancement factor of dendritic Au/Ag bimetallic nanostructure (Ag180s-Au30s) is calculated to be 6.1 × 10 8 , which is much larger than those of Ag@Au concave cuboctahedra (4.8 × 10 6 ) [20], hybrid Au−Ag nanochains (2.4 × 10 7 ) [34], double-shelled Au/Ag nanoboxes (6.6 × 10 5 ) [35], and flower-like 3D Ag-Au heteronanostructures (1.17 × 10 7 ) [36].…”

Ag Nanostructures with Spikes on Adhesive Tape as a Flexible Sers-Active Substrate for In Situ Trace Detection of Pesticides on Fruit Skin

“…However, it is also noted that an optimal length should be taken into consideration-in the case of Ag NSPs, e.g., the local electromagnetic field weakens as it moves from the core of the structure to its tip, leading to weaker SERS signals with spikes longer than the optimal length [33]. In addition, these spiky nanostructures present an advantage over the commonly-used nanospheres as they provide a larger specific surface area that contributes to the enhancement of signals [34]; spiky nanostructures take advantage of the lightning rod effect in providing highly enhanced electric fields [35].…”

Modulation of interparticle gap for enhanced SERS sensitivity in chemically stable Ag@Au hetero-architectures

“…The chemical stability of the Ag and Ag@Au nanoparticle substrates in harsh environments was assessed using a similar method to that reported in previous studies. 12,13,33 Briefly, the substrates were submerged in a 0. In order to quantify the degree of protection to the Ag nanoparticles provided by the Au films, the SERS spectra of R6G (10 -7 M) on the pure Ag nanoparticle, Ag@Au4, Ag@Au8 and Ag@Au12 substrates were collected prior to, and following immersion in H 2 O 2 , and the intensity of 606 cm -1 peak was plotted as shown in Fig.…”