Gold@silver bimetal nanoparticles/pyramidal silicon 3D substrate with high reproducibility for high-performance SERS

Abstract

A novel and efficient surface enhanced Raman scattering (SERS) substrate has been presented based on Gold@silver/pyramidal silicon 3D substrate (Au@Ag/3D-Si). By combining the SERS activity of Ag, the chemical stability of Au and the large field enhancement of 3D-Si, the Au@Ag/3D-Si substrate possesses perfect sensitivity, homogeneity, reproducibility and chemical stability. Using R6G as probe molecule, the SERS results imply that the Au@Ag/3D-Si substrate is superior to the 3D-Si, Ag/3D-Si and Au/3D-Si substrate. We also confirmed these excellent behaviors in theory via a commercial COMSOL software. The corresponding experimental and theoretical results indicate that our proposed Au@Ag/3D-Si substrate is expected to develop new opportunities for label-free SERS detections in biological sensors, biomedical diagnostics and food safety.

Label-free highly sensitive probe detection with novel hierarchical SERS substrates fabricated by nanoindentation and chemical reaction methods

“…The Raman intensity can be enhanced further due to the formation of nanoclusters. Other scholars have already obtained similar conclusions [10,17,32]. Copper nanowires were soaked in AgNO 3 solution by Wang et al [10].…”

“…A local electric field enhancement is caused when a single nanoparticle comes in contact with the sample and the "hot spots" are formed by multiple nanoparticles to improve the electric field intensity and local electromagnetic field. Zhang et al [32] deposited a Ag film of 30 nm and a Au film of 10 nm on the roughened silicon surface by the thermal evaporation method. The higher Raman intensity of the sample at 10 −8 mol/L was detected on the Au@Ag particle substrate.…”

High-performance SERS substrate based on hybrid structure of graphene oxide/AgNPs/Cu film@pyramid Si

“…Compared with the AgNPs/PCu@Si substrate, the GO/AgNPs/PCu@Si substrates exhibit an enhancement of about 3 times in the EF values resulting from the CM of the GO. The EF of the GO/AgNPs/PCu@Si substrate is 1.7 × 10 3 times larger than that of the Au@Ag/3D-Si substrate30, 6.06 × 10 3 times larger than the G/AgNP array substrates31. The excellent SERS sensitivity of the GO/AgNPs/PCu@Si substrate can be attributed to the combined action of the pyramid of the PCu@Si, the coupling of GO and plasmonic AgNPs, and the local electric field enhancement between the AgNPs and Cu film.…”

Ag‐Nanoparticles‐Decorated Ge‐Nanowhisker Grafted on Carbon Fiber Cloth as Flexible and Effective SERS Substrates

“…[1][2][3][4][5][6][7] To carry out perfect SERS measurement, SERS substrates are supposed to not only have high-density "hot spots" with highly concentrated electromagnetic (EM) field to make a significant contribution to the Raman signal enhancement, but also have good uniformity to guarantee reproducible SERS measurements. [8][9][10][11][12][13][14] Since ordered three-dimensional (3D) micro/nanostructures (mainly plasmonic nanoparticles) with large surface area can support high-density "hot spots" while ensuring a good uniformity, various SERS substrates of noble metal nanoparticles (NPs) decorated 3D nanostructures were constructed, [15][16][17][18] such as Ag-NPs@ZnO nanowire arrays, [19] Ag-NPs@vertical graphene-nanosheet, [20] Ag-nanocubes@photolithographic microstructures and Pt@TiO 2 nanotube arrays. [21][22] In particular, flexible 3D nanostructures are more desirable for constructing SERS substrates, because of the fragile and inconvenience performance of traditional rigid templates.…”