Novel Surface Enhanced Raman Spectroscopy Nanocomposite Platforms: Polycaprolactone Electrospun Nanofibrous Films Carrying Plasmonic Gold Nanoparticles Prepared by a Sonochemical Reduction and Simultaneous Deposition Method

Raman spectroscopy is a powerful optical technique developed for detection and chemical analysis of target molecules at trace levels. In order to increase precision “surface enhencement” (SE) is needed. This study attempts to prepare novel SERS platforms based on electrospun polycaprolactone (PCL) nanofibrous films carrying plasmonic gold nanoparticles (AuNPs). PCL was synthesized using ring opening polymerization and were characterized using Gel Permeation Chromatography (GPC), Fourier-Transform Infrared Spectroscopy (FTIR), and Proton Nuclear Magnetic Resonance ( ¹ H-NMR) . Then PCL nanofibrous films were produced in a semi-continuous electrospinning system and charaterized using X-Ray Diffraction (XRD). Morphological analysis of the PCL nanofibrous structures were demostrated by Scanning Eectron Microscopy (SEM). Mechanical properties and wettabilities of the films were measured. AuNPs were formed on the nanofibrous surfaces by a sonochemical reduction/simultaneous deposition process using water soluble HAuCl ₄ with four different concentrations in a wide range (0.005, 0.01, 0.05 and 0.1 mM) - at the predetermined conditions. Depositions were followed by electron microscopy imaging. Raman spectral analysis was performed by using methylene blue as a typical SERS marker to exhibit the surface enhancement effects of the plasmonic nanoparticles on the PCL electrospun nanofibrous platforms - which were very significant.