(559j) Hydrophobic Nanofibers With Silver Nanoparticles As a Surface Enhanced Raman Spectroscopy Substrate

Surface enhanced Raman spectroscopy (SERS) has emerged as a platform for ultrasensitive detection of analytes. A key issue in the production of SERS substrates is the production of substrates with high enhancement, reproducibility, and stability. Electrospun polymeric nanofibers incorporating metal nanoparticles have shown potential as a SERS substrate. Existing SERS-active nanofibers have primarily been synthesized with water dissolvable polymers, which are not suitable for detection of biological analytes in aqueous solutions. We show the production of a SERS-active polycaprolactone (PCL) fiber containing silver nanoparticles (AgNP). Electrospinning caused alignment of silver nanoparticles along the axis of the fiber. The PCL-AgNP fiber exhibited at least 10-fold enhancement of the Raman spectra of rhodamine 6G (R6G). The hydrophobic surface of PCL improved signal enhancement of samples dried on the surface, due to the reduced contact area of the droplet and resulting increase in surface concentration. The SERS signal is reproducible across the mat and between electrospinning syntheses. Moreover, we show improved stability of signal enhancement within the fiber compared to silver aggregates. This SERS substrate provides a cost-effective, highly reproducible and stable platform for the sensitive detection of molecules in aqueous solutions.