SERS-active substrate assembled by Ag NW-embedded porous polystyrene fibers.

Here we demonstrate a novel SERS-active substrate assembled by silver nanowire (Ag NW)-embedded porous polystyrene (PS) fibers. Ag NWs are synthesized through a glycerol-mediated solvothermal method firstly, then electrospun into PS porous fibers. The as-synthesized Ag NWs are embedded in PS fiber and aligned orderly along the axial direction. Porous structure appears in PS fiber due to the phase separation induced by rapid evaporation of solvents. Large amounts of holes not only greatly improve the sample collection efficiency of the SERS-active substrate, but also significantly facilitate the adsorption of target molecules on the surface of Ag NWs, thus increasing the probability of enhancement of target molecules. In addition, compared with polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), PS has better solvent resistance. The detection limit of 4-aminothiophenol (4-ATP) on our fabricated electrospun fiber mats is 10 -7 M, and the electrospun fiber mats showed good reproducibility of SERS signal detection. This study proposes a feasible strategy for the large-scale preparation of flexible SERS-active substrate assembled by Ag NW-embedded porous PS fibers. The produced flexible SERS substrates may have potential application in wearable sensors for the trace detection of chemical and biological molecules.