Intrinsic Raman signal of polymer matrix induced quantitative multiphase SERS analysis based on stretched PDMS film with anchored Ag nanoparticles/Au nanowires

Aiming to realize a reliable quantification multiphase surface-enhanced Raman scattering (SERS) detection, we designed and synthesized a novel flexible and transparent SERS substrate based on PDMS film modified with forest of Ag/Au nanowires (NWs) through two steps of seed-mediated growth and magnetron sputtering coating. Owing to the flexibility of the polymer matrix, the SERS activity of the Ag/Au NWs/PDMS film was improved by a mechanical stretch strategy, showing a remarkable enhancement factor of 6.74 × 106. Moreover, the versatile hybrid SERS substrate could be utilized to trace pesticides under various conditions. The monitoring of 2-naphthalenethiol with limit of detection (LOD) of 10−9 M in atmosphere, the detection of methyl parathion (MP) with LOD of 10−6 mg/mL on the surface of tomato, and the identifying of MP with LOD of 10−5 mg/mL in soybean oil were all effectively realized. Particularly, the poor linear relationships in the three detections were significantly corrected to guarantee the quantitative analysis by using the intrinsic SERS peak of PDMS as internal standard. The multifunctional Ag/Au NWs/PDMS film developed here is expected to find great potential practical applications in rapid and sensitive on-site monitoring of food and environmental security.