Low-cost SERS substrate featuring laser-ablated amorphous nanostructure

In this work, we aimed at fast and scalable manufacturing of low-cost SERS substrates using ultrashort-pulse laser-induced plasma-assisted ablation (LIPAA) of soda-lime glass. A two-step approach of amorphous nanostructure formation on the glass surface and subsequent deposition of 170 nm silver layer resulted in homogenous SERS-active substrates covered with nanostructures of around 100 nm in diameter, forming 1-3 mu m size dendrimers. The average enhancement factor (EF) evaluated using thiophenol was 3.0 x 105, while the surface activity was found to be consistent at any given point of substrates. Relatively modest EF was explained by amorphous, rounded-shaped features on soda-lime glass formed during the LIPAA-induced melting and subsequent solidification. That resulted in a lesser amount of hot spots but increased surface homogeneity. The use of soda-lime glass to fabricate SERS substrates promises a cheaper and scalable alternative to more widely used sapphire and other material substrates opening prospects for low-cost routine SERS testing with high reproducibility in chemistry, medical, forensic, and environmental sciences.