Fabrication of SERS Substrates by Roll-to-Roll Hot Embossing

Surface-enhanced Raman spectroscopy (SERS) combines the high specificity of Raman scattering with a high sensitivity due to an enhancement of the electromagnetic field by metallic nanostructures. Multiple micro- and nanostructuring methods have been used to fabricate SERS-structures [1–3]. We present an approach to create enhancing arrays of nanopillars [4] by roll-to-roll (R2R) hot-embossing and to functionalize them with a gold layer. The R2R hot embossing process is shown in principle in Fig. 55.1 on the left. The setup mainly consists in two rotating cylinders (one micro- or nanostrcutured) that can be pressed against each other and additionally heated up to exceed the glass transition temperature of the polymer foil in between. The embossing parameters mainly determine the results [5]. We have investigated the influence of the embossing temperature and pressure. With the identified parameter setting we can show the uniform transfer of the nanopillars like shown in Fig. 55.1 on the right. The setup and the result of a Raman measurement of the analyte rhodamine 6G (Rh6G) on a SERS substrate and an unstructured reference substrate is shown in Fig. 55.2. In a following step this SERS substrate can be integrated into a microfluidic chip by manufacturing one master for the microstructure and the nanostructures. Our work show a way to a low cost fabrication of tailor-made sensor chips for SERS analyse.