Fabrication of patterned small blocks of nanogold-loaded PDMS and its potential as reproducible SERS substrate

A new method for fabricating highly patterned small blocks of nanogold-loaded PDMS, named as PDMS/Au, and their surface-enhanced Raman scattering (SERS) activity are reported. This nanocomposite is based on nanogold impregnated into polydimethylsiloxane (PDMS) elastomer, prepared previously as patterned small blocks using a polypropylene template (PPT), containing 120 small holes. All holes of PPT have the same dimensions 0.5 cm (depth) x 0.6 cm (diameter), allowing to prepare 120 patterned PDMS blocks per batch. After the reduction reaction of HAuCl4 in ethanol medium, the colorless PDMS blocks turned wine red, which was a visual indication of nanogold formation. Using para-mercaptobenzoic acid (p-MBA) as probing molecule, SERS spectra were investigated. The PDMS/Au substrate exhibited reproducibility of the p-MBA (10(6) mol L-1) Raman signal. The convenience for preparing, stability, and using makes it a promise candidate for SERS application in the fast lab and field analysis. (C) 2019 Elsevier B.V. All rights reserved.