Self-Assembly of Strain-Adaptable Surface-Enhanced Raman Scattering Substrate on Polydimethylsiloxane Nanowrinkles

Flexible surface-enhanced Raman scattering (SERS) substrates adaptable to strains enable effective sampling from irregular surfaces, but the preparation of highly stable and sensitive flexible SERS substrates is still challenging. This paper reports a method to fabricate a high-performance strain-adaptable SERS substrate by self-assembly of Au nanoparticles (AuNPs) on polydimethylsiloxane (PDMS) nanowrinkles. Nanowrinkles are created on prestrained PDMS slabs by plasma-induced oxidation followed by the release of the prestrain, and self-assembled AuNPs are transferred onto the nanowrinkles to construct the high-performance SERS substrate. The results show that the nanowrinkled structure can improve the surface roughness and enhance the SERS signals by ∼4 times compared to that of the SERS substrate prepared on flat PDMS substrates. The proposed SERS substrate also shows good adaptability to dynamic bending up to ∼|0.4| 1/cm with excellent testing reproducibility. Phenolic pollutants, including aniline and catechol, were quantitatively tested by the SERS substrate. The self-assembled flexible SERS substrate proposed here provides a powerful tool for chemical analysis in the fields of environmental monitoring and food safety inspection.