Abstract
Surface-enhanced Raman spectroscopy (SERS) is a very promising analytical technique for the detection and identification of trace amounts of analytes. Among the many substrates used in SERS of great interest are nanostructures fabricated using physical methods, such as semicontinuous metal films obtained via electron beam physical vapor deposition. In these studies, we investigate the influence of morphology of semicontinuous silver films on their SERS properties. The morphologies studied ranged from isolated particles through percolated films to almost continuous films. We found that films below the percolation threshold (transition from dielectric-like to metal-like) made of isolated silver structures provided the largest SERS enhancement of 4-aminothiophenol (4-ATP) analyte signals. The substrate closest to the percolation threshold has the SERS signal about four times lower than the highest signal sample.
Highlights
Noble metal nanostructures exhibit exceptional optical properties
The semicontinuous silver films (SSFs) were prepared on glass substrates using electron-beam physical vapor deposition (PVD)
The SERS activity of studied substrates was explained with relation to their morphologies and optical properties
Summary
Noble metal nanostructures exhibit exceptional optical properties. They can efficiently absorb and/or scatter visible and near infrared electromagnetic radiation [1]. The spectral position of an LSPR depends on the dielectric constant of the metal, surrounding dielectric, shape and size of the nanostructure, and its orientation with respect to the electric component of the electromagnetic field [1,2]. The electric field near the surface of metallic nanostructures can be greatly enhanced and localized in nanoscale regions called “hot spots” [3]. These “hot spots” can be utilized in surface-enhanced Raman spectroscopy (SERS) [4], allowing for the detection of trace amounts of Beilstein J.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
