Substrate for SERS sensor realized by DELIL (Double Exposure Laser Interference Lithography) technique

We have realized a 3D substrate for surface-enhanced Raman scattering (SERS) sensor with DELIL (Double Exposure Laser Interference Lithography) technique and silver nanoparticles (Ag-NPs) functionalized with an appropriate aptamer. The 3D substrates were obtained by means of soft mold technique in thin layer of sol-gel Ti/TMSPM on silicon substrate using intermediate stamp fabricated in a photosensitive material. The stamp was in turn produced with a Lloyd's mirror set up by means of double exposition (Ar+ laser at 364 nm, 23 mW) of a photopolymerizable thin film at two mutually orthogonal orientation.The obtained 3D gratings have regular cross-weave texture with holes and pillars. The Ag-NPs were deposited by drop-casting on the 3D substrates and they arranged themselves inside the holes. This controlled Ag-NPs distribution allows the system to be a potential candidate for a good SERS sensor. The easy replication of the 3D substrates from a single stamp makes this technique attractive for applications in analytic and environmental fields.