Surface-enhanced Raman spectroscopy (SERS) is a well-known label-free analytical technique for chemical and biological detection. Electromagnetic enhancement near the nanostructured surfaces contribute to the SERS performance. However, the substrate-based nanostructured SERS surfaces are conventionally fabricated by time- and resource-intensive techniques. Herewith, a cost-effective and scalable process chain to fabricate disposable thermoplastic SERS substrates is investigated. The surface design includes a multiscale topography that consist of single-tier laser-induced periodic surface structures (LIPSS) encircled by two-tier hierarchical structures (HS). Different types of LIPSS were investigated, generated by linear and circular polarisation of the laser. The process chain employed to produce high performance SERS substrates include, first, ultrashort laser-enabled fabrication of a textured metallic masters and then replication of functional topographies on Cyclic Olefin Copolymer (COC) using hot embossing and finally mask-coating the LIPSS ‘hot spot’ with gold for an electromagnetic enhancement. The HS topographies facilitated the superhydrophobic evaporation of samples to enrich the analytes onto the SERS ‘hot spot’ on the COC substrates. An electromagnetic enhancement factor of 107 was achieved on the SERS substrates employing the proposed process chain. The SERS enhancement of such multi-scale functional topography was analysed and a detection limit of up to 10-7 M of methylene blue and 4-MBA was achieved. The proposed cost-effective process chain can pave the way for the broader use of SERS for detecting analytes in food and agricultural sectors.
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