Ag-decorated TiO2 Nanofibers for Surface-enhanced Raman Scattering

Abstract

In this report, SERS substrates based on Ag-decorated TiO2 nanofibers electrospun on a glass substrate (Ag/TiO2/glass) were successfully prepared using electrospinning and photodeposition methods. XRD pattern demonstrated that the crystalline structure of TiO2 nanofibers (TiO2 NFs) consisted of both anatase and rutile phase. SEM images show that the randomly oriented on glass substrate TiO2 NFs’ diameters are in the range of 150 nm-300 nm and their lengths are up to a few micrometers. After 15-minute photodeposition, Ag NPs with average diameter of about a few tens of nanometers were uniformly and densely decorated on TiO2 NFs surface. The Ag/TiO2/glass SERS substrate was then immersed in 0.01 mM, 0.1 mM, and 1 mM 4-mercaptobenzoic acid (4-MBA) solution, and was afterwards investigated by UV-Vis absorption and Surface-enhanced Raman Scattering (SERS) spectra. The preliminary results show that the change in UV-Vis absorption corresponds well to the Raman peak intensity upon the adsorption of probed molecules. This might open up a pathway in the detection and identification of probed molecules based on colorimetric-sensing and SERS-sensing.