Facile Shape-Controlled Fabrication of Copper Nanostructures on Borophosphate Glasses: Synthesis, Characterization, and Their Highly Sensitive Surface-Enhanced Raman Scattering (SERS) Properties

We demonstrate air-stable copper-doped nano structured borophosphate samples, which were prepared by a facile, low cost, and green synthesis method. The thermal annealing, in a reducing hydrogen atmosphere, enables the formation of metallic copper nanostructures, which was confirmed by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and optical absorption. The optical spectra show a main intense surface plasmon resonance (SPR) band centered at 579 nm. The shapes of the nanostructures, morphology, and thickness of the copper nanostructures coating are chosen to be suitable for SERS applications. These samples exhibited very high SERS enhancement factors (EF), depending on thermal annealing time, with excellent reproducibility. The estimated EFs have been found in the range, between 10(7) and 10(8).