Dodecagonal plasmonic quasicrystals for phage-based biosensing

In this work, we fabricate and characterize a novel sensitive 2D SERS (Surface Enhanced Raman Spectroscopy) substrate made of plasmonic nanocavities (NCs) in a photonic quasicrystal arrangement characterized by a 12-fold rotational symmetry. Our SERS device is capable of detecting chemisorbed bacteriophages at a fMolar range. Most importantly, the paper presents for the first time a study on the procedure to functionalize the plasmonic quasi- crystal with bacteriophages of the Podoviridae family. The immobilization of the phages on the plasmonic substrate has been studied and verified through SERS measurements. A new stable peak, visible in the SERS spectra at 1326 cm-1 with a giant amplification greater than 60 times, confirms the immobilization of the phages on the substrate. This functionalization approach can be used also for other types of phages or plasmonic sensors and hence, our achievements could allow the development of novel systems for the specific detection of different species of bacteria.