Preparation of Plasmonic Au-TiO2 Thin Films on a Transparent Polymer Substrate

Coatings

卷:10

Filipe Vaz¹  Cláudia Lopes¹  Joel Borges¹  Diana I. Meira¹  Marco S. Rodrigues¹ 

[1] Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal;

关键词: thin films;    reactive magnetron sputtering;    gold nanoparticles;    titanium dioxide;    poly(dimethylsiloxane) substrate;    localized surface plasmon resonance;   

DOI  :  10.3390/coatings10030227

来源: DOAJ

【 摘 要 】

In this work, plasmonic thin films composed of Au nanoparticles embedded in a TiO₂ matrix were prepared in a transparent polymer substrate of poly(dimethylsiloxane) (PDMS). The thin films were deposited by reactive DC magnetron sputtering, and then subjected to heat treatment up to 150 C in order to promote the growth of the Au nanoparticles throughout the TiO₂ matrix. The transmittance spectrum of the thin films was monitored in situ during the heat treatment, and the minimum time required to have a defined localized surface plasmon resonance (LSPR) band was about 10 min. The average size of Au nanoparticles was estimated to be about 21 nm—the majority of them are sized in the range 10-40 nm, but also extend to larger sizes, with irregular shapes. The refractive index sensitivity of the films was estimated by using two test fluids (H₂O and DMSO), and the average value reached in the assays was 37.3 ± 1.5 nm/RIU, resulting from an average shift of 5.4 ± 0.2 nm. The results show that it is possible to produce sensitive plasmonic Au-TiO₂ thin films in transparent polymer substrates such as PDMS, the base material to develop microfluidic channels to be incorporated in LSPR sensing systems.

【 授权许可】

Unknown