摘要
Dual fs laser structuring creates hierarchical PDMS SERS substrates. • Secondary laser processing increases nanoscale roughness and hotspots. • Detection limitation down to 10 −10 M with high linearity. • Excellent uniformity (RSD 2.57%) and reusability (<4% decay). • Flexible substrate enables adhesive sampling on curved surfaces. Flexible and sensitive surface-enhanced Raman scattering (SERS) substrates are essential for real-world applications such as wearable sensors and on-site molecular detection. We developed two polydimethylsiloxane (PDMS)-based flexible SERS substrates via the replication of femtosecond (fs) laser-nanostructured titanium (Ti) templates: a single-processed Ti-Fs-PDMS substrate and a dual-processed Dual-Fs-PDMS substrate, the latter incorporating an additional fs laser treatment to enrich nanoscale surface features. Gold was thermally deposited onto the structured PDMS to introduce plasmonic enhancement. The dual-structured substrate exhibits higher roughness and hydrophobicity (water contact angle >130°). SERS performance was evaluated using Rhodamine 6G (R6G) and malachite green (MG), revealing high sensitivity with a detection limit as low as 10 −10 M for Dual-Fs-PDMS and excellent signal linearity (R 2 > 0.99). Furthermore, the Dual-Fs-PDMS substrate exhibits superior signal uniformity (RSD = 3.203%), reusability, mechanical robustness, and good long-term stability over 180 days, as well as the capability for in situ detection on curved surfaces. Three-dimensional electromagnetic field simulations based on AFM-acquired topography indicated that the Dual-Fs-PDMS substrate exhibits a stronger local electric field and a higher density of “hot spots”, correlating with its enhanced SERS performance. These results highlight the potential of Dual-Fs-PDMS as a flexible and high-performance SERS platform for practical applications. Download: Download high-res image (213KB) Download: Download full-size image
危险品化学品经营许可证（带存储）