Design and synthesis of surface-enhanced Raman scattering active surfaces

In this project silver nanoparticles (AgNPs) were deposited over different solid surfaces, to produce suitable substrates to be used in surface enhanced Raman spectroscopy. Silicon wafer, filter paper, and chitosan films were used as solid surfaces. AgNPs with shapes of quasi-spheres (QS1 and QS2), circular nanoplates (TN1), and quite small (TN2), small (TN3), medium (TN4), and large (TN5) triangular nanoplates were prepared through the polyol method. Colloidal dispersions of these nanoparticles were characterized by UV-Vis spectroscopy showing the characteristic localized surface plasmon (LSP) bands. The SEM micrographs of TN1, TN2, TN3, TN4, TN5, and QS2 exhibited particles with nanometric size. SERS measurements of TN4 and QS2 nanoparticles over silicon wafer substrate were carried out using rhodamine 6G as probe molecule and with a wavelength of 633 nm. TN4 and QS2 showed SERS effect, being the last higher. It could be attributed to the anisotropy and the localized surface plasmon (LSPR) of the nanoparticles. The band of 1344cm-1 for QS2 presented an enhancement factor of approximately 1.6*102 times. Therefore, the QS2/Silicon Wafer substrate could be used as an effective SERS substrate.

• 1. Verfasser: Caisachana Lozada, María Judith (author)
• Format: bachelorThesis
• Sprache: eng
• Veröffentlicht: 2022
• Schlagworte: Espectroscopia Raman; Nanopartículas de plata; Síntesis de poliol; Raman spectroscopy; Silver nanoparticles; Polyol synthesis
• Online Zugang: http://repositorio.yachaytech.edu.ec/handle/123456789/471