Facile One-Step Deposition of Ag Nanoparticles on SiO<sub>2</sub> Electrospun Nanofiber Surfaces for Label-Free SERS Detection and Antibacterial Dressing
Menghui Wan, Haodong Zhao, Lichao Peng, Yanbao Zhao, Lei Sun
Abstract
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, SiO2 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 SiO2 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 SiO2 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.