New branched flower-like Ag nanostructures for SERS analysis

In this work, metallic silver flower-like and aerogel-like nanostructures deposited onto hydrophobic dielectric substrates (HF-treated Si and PDMS) showed interesting potentialities as solid SERS substrates aimed to high sensitive molecular detection and quantitation. In detail, the nanostructures were incubated in 4-MBA solutions at 10(-2) M-10(-9) M concentrations. The quantitative analysis confirmed a monotonic increase of the SERS signal intensity as a function of the 4-MBA concentration, following a Langmuir model, thus suggesting a chemisorption phenomenon. The best homogeneity and adhesion strength in liquid media of Ag nanostructures to the solid substrates were reached for the flower-like systems and the aerogel-like ones compared to traditional polyhedral nanostructures (taken as reference substrate), thus making them extremely appealing as a solution for the development of SERS-based sensors.