Preparation of a monolayer array of silica@gold core-shell nanoparticles as a SERS substrate

• Published in: Optik (Stuttgart) 2020-11, Vol.221, p.165274, Article 165274
• Main Authors: Gu, Ciyong, Man, Shi-Qing, Tang, Junqi, Zhao, Zhimin, Liu, Zhenlu, Zheng, Zhiyuan
• Format: Article
• Language: English
• Subjects: Crystal violet (CV); SERS; Silicon wafer; SiO2@Au NP; Spin-coating
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2020.165274

In this work, we report the preparation of monolayer silica@gold core-shell nanoparticle (SiO2@Au NP) nanostructures, which combines spin-coating, nanoscale masking and in situ reduction methods. Using this approach, a potential SERS substrate based on a composite particles of SiO2@Au NP monolayer array was fabricated. The surface morphology and optical properties of the samples were performed by scanning electron microscopy (SEM) and ultraviolet-visible (UV–vis) spectrophotometry. To study the SERS properties of the substrate, crystal violet (CV) was selected as the probe molecule. The Raman activity of characteristic vibrational bands of CV showed better when the excitation wavelength was close to the plasma peak of the SiO2@Au NPs. In addition, the Raman signal of the probe molecule on the SERS substrate presented good homogeneity, reproducibility and stability, also reproduce the SERS spectra after three weeks. Furthermore, the Raman enhancement factor (1.4×107), the detection limit (1×10−8 mol/L) and the relative standard deviation (RSD, 14.07 %) were evaluated. Our approach has potential advantage in the fabrication of viable solid SERS substrates that provides a possibility for commercialization used in nondestructive testing, food testing and detection of low-concentration.