The LSPRs arise from the excitation of a collective electron oscillation within the metallic nanostructure induced by the incident light, leading to enormous optical local-field enhancement and a dramatic wavelength-selective photon scattering at the nanoscale [20–23]. The exceptional optical properties introduced by LSPRs have spurred tremendous efforts to design and fabricate highly SERS-active substrates
for molecular sensing. The most studied and best established systems are substrates sprayed with Ag or Au colloids that give high SERS signals at some local ‘hot junctions’ [24]. In order to fabricate noble nanoparticle arrays with high SERS activity and improve the uniformity, lithographic techniques Selleck Thiazovivin have been employed. We
have recently reported a relatively simple approach in fabricating uniform gold nanocrystal-embedded nanofilms via a conventional magnetron sputtering method. In this method, one can more conveniently RG7112 nmr assemble noble metals with precise gap control in the sub-10-nm regime [25] than any other method. As a continual effort in supporting the above claim, here we report further evidence such as visible absorption spectra of Vistusertib molecular weight the Au film on indium tin oxide (ITO) glass substrates, the blend Methane monooxygenase films of poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) and poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) on ITO glass substrates, and the SERS measurements of molecules adsorbed on gold nanocrystals deposited on ITO glass substrates. Our results suggest that the continuous ultrathin nanofilm can obviously enhance visible-range absorption in the active layer of solar cells and obtain an ultrasensitive SERS-active coating. Methods The fabrication of continuous ultrathin Au nanofilms Our approach is based on the formation of Au nanofilms
on the buffer layer surface of PEDOT:PSS or on ITO glass utilizing magnetron sputtering deposition of metal atoms. The ITO-coated glass substrate was first cleaned with detergent, then ultrasonicated in acetone and isopropyl alcohol for further cleaning, and subsequently dried in a vacuum oven at 80°C for 3 h. PEDOT:PSS films with thicknesses of 30 nm are prepared via spin coating on top of the ITO glass and cured at 130°C for 10 min in air. On top of the freshly prepared PEDOT:PSS layer, metallic gold are sputtered by magnetron sputtering in an electrical current of 0.38 A, vacuum of 0.15 Pa, Ar flux of 25 sccm, and discharge of 1 s. The ITO/Au nanofilm is fabricated in an identical magnetron sputtering manner.