A highly sensitive surface-enhanced Raman scattering substrate prepared on a hydrophobic surface using controlled evaporation.

In the present work, we report the fabrication of a surface-enhanced Raman spectroscopy (SERS) substrate on a simple and easily fabricable hydrophobic surface. The substrates are prepared by slow and fast evaporation of a droplet of silver nanoparticle suspension in water. The corresponding identifiers for two substrates are "s_evp" and "f_evp" respectively. It is found that the dried spot size is small on s_evp compared to that on f_evp. This also minimizes the coffee stain effect and enriches the spot in a better way on s_evp compared to f_evp. Consequently, using SERS experimentation on our lab-built setup, concentration as low as 2.5*10 -12 M of rhodamine 6G molecules was detected on s_evp compared to 2.5 × 10 -10 M on f_evp. The proposed s_evp SERS substrate is much easier to fabricate and easy to use compared to super-hydrophobic SERS substrates.