Facile One-Step Deposition of Ag Nanoparticles on SiO 2 Electrospun Nanofiber Surfaces for Label-Free SERS Detection and Antibacterial Dressing.

The fabrication of highly active and free-standing surface-enhanced Raman scattering (SERS) substrates in a simple and low-cost manner has been a crucial and urgent challenge in recent years. Herein, SiO 2 nanofiber substrates modified with size-tunable Ag nanoparticles were prepared by the combination of electrospinning and in situ chemical reduction. The results demonstrate the presence and uniform adsorption of Ag nanoparticles on the SiO 2 matrix surface. The free-standing composite nanofibrous substrates show high-performance SERS response toward 4-mercaptophenol and 4-mercaptobenzoic acid, and the detection limit can be as low as 10 -10 mol/L. Most importantly, the as-prepared substrate as a versatile SERS platform can realize label-free detection of bio-macromolecules of bacteria, i.e., Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ). Furthermore, the substrates also possess outstanding antibacterial activities against S. aureus and E. coli . Briefly, the significance of this study is that size-tunable Ag nanoparticles can be decorated on SiO 2 nanofiber surfaces with triethanolamine as a bridging and reducing agent through a one-pot reaction, and the as-prepared nanofibrous membranes are expected to act as a candidate for label-free SERS detection as well as antibacterial dressing.