Magnetic-plasmonic Ni nanotubes covered with gold for improvement of SERS analysis

The paper describes the synthesis of substrate for surface enhanced Raman spectroscopy (SERS) based on magnetic nickel nanotubes (Ni NTs). For the success application of Ni NTs in quantitative SERS analysis of organic molecules by the example of Rhodamine 6G (R6G), electroless deposition of gold (I) on Ni NTs in alkali media was performed. The purity and uniformity of the gold layer has been proven by methods of XRD, SEM-EDX, XPS and FTIR analysis. The magnetic properties of the obtained magnetic Ni-Au NTs measured by VMS did not change compared to the initial Ni nanotubes. The efficiency of substrates with NiAu NTs is determined by the optical properties of the substrate (the position of the plasmon resonance peak). The substrates with scattered nanotubes having a plasmon resonance position at 530 nm are the most effective for use in SERS when using a laser with a wavelength of 532 nm, as exemplified by the spectra of Radomin 6G. SERS analysis of R6G using Ni-Au NTs in concentration range from 10(-3) to 10(-8) led to average enhancement factor of 8.10(5). (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The paper describes the synthesis of a substrate for surface enhanced Raman spectroscopy (SERS) using magnetic nickel nanotubes (Ni NTs) and its application in quantitative analysis of organic molecules. The success of the substrate is achieved by depositing a gold layer on the Ni NTs and the purity and uniformity of the gold layer are confirmed through various analysis methods. The study shows that the magnetic properties of the obtained magnetic Ni-Au NTs remain unchanged compared to the initial Ni nanotubes, and the substrates exhibit high SERS enhancement efficiency.