Nanoporous gold thin films synthesised via de-alloying of Au-based nanoglass for highly active SERS substrates

ABSTRACT

Nanoporous gold thin films have been fabricated through chemical de-alloying of Au-based nanoglass with a nanocolumnar structure, with composition Au₄₀Cu₂₈Ag₇Pd₅Si₂₀ (at.%), that had previously been deposited by magnetron sputtering. By varying the de-alloying conditions, gold ligaments ranging from 20 to 100 nm were obtained. The microstructure and chemical composition of the as-prepared films were characterised by various techniques. Surface-enhanced Raman scattering (SERS) of thin films was investigated using rhodamine 6G. The results indicate that the main microstructural features with interconnected ligaments and defects of nanoporous gold result in significant SERS enhancement.

KEYWORDS:

• Nanoporous thin film
• chemical de-alloying
• nanoglass
• surface-enhanced Raman scattering

Acknowledgements

Dr Alessandro Damin of Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces) from Università di Torino is kindly acknowledged for the SERS experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the funding scheme of the European Commission, Marie Curie Actions – Initial Training Networks (ITN) in the frame of the project VitriMetTech-Vitrified Metals Technologies and Applications in Devices and Chemistry, 607080 FP7-PEOPLE-2013-ITN and also by BINGO Project-Torino_call2014_L2_146 for Compagnia di San Paolo.