Fabrication of Ag/PDMS Substrate of High-Density Hot Spots and Its Application in in situ Detection

Intersecting Ag nanoplates abounding with hot spots were formed on rigid DVD while spherical nanoparticles were produced on flexible PDMS by simple replacement reaction. Ag nanoplates of high SERS activity were ingeniously transferred onto PDMS by further growth of embedded nanoplates. The obtained Ag/PDMS substrates were endowed with high sensitivity, desirable uniformity, and good stability under bending. Combined with the transparency and flexibility of PDMS, the ability of in-situ detection of Ag/PDMS was demonstrated, holding great potential for fast practical detection. Through a replacement reaction approach, Ag nanostructure was easily prepared on economical digital video disc (DVD) and polydimethysiloxane (PDMS) with surface structure duplicating from the former. Distinct nanoscale morphology was observed, featuring intersecting Ag nanoplates with abundant hot spots on the DVD and spherical Ag nanoparticles on the PDMS. Surface-enhanced Raman scattering (SERS) spectra, using crystal violet as a probe, revealed a superior enhancement effect in Ag/DVD versus that in Ag/PDMS. Considering the desirable flexibility and transparency of PDMS for in situ detection, we further developed a protocol to introduce intersecting Ag nanoplates onto the PDMS surface. The resulting Ag/PDMS substrate was endowed with remarkable sensitivity, excellent uniformity and good stability under mechanical bending. Furthermore, effective in situ detection of malachite green on fish was demonstrated, highlighting the great potential of our approach for the in situ detection of target molecules on a curved surface.

Automated summary

Utilizing a replacement reaction approach, distinct Ag nanostructures were prepared on DVD and PDMS surfaces, with high SERS activity Ag nanoplates ingeniously transferred onto PDMS. The resulting Ag/PDMS substrates exhibited remarkable sensitivity, uniformity, and stability, demonstrating the potential for in situ detection on curved surfaces.