Experimental and DFT studies of copper nanoparticles as SERS substrates

• Published in: Applied physics. A, Materials science & processing Vol. 129; no. 4
• Main Authors: Amador-Martínez, J. D., Flores-López, N. S., Hernandez-Martínez, A. R., Calderón-Ayala, G., Bocarando-Chacon, J., Cayetano-Castro, N., Martínez-Suarez, F., Leal-Pérez, J. E., Cortez-Valadez, M., Britto Hurtado, R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2023; Springer Nature B.V
• Subjects: Absorption spectra; Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Copper; Density functional theory; Gelatin; Machines; Manufacturing; Materials science; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Raman spectroscopy; Substrates; Surface plasmon resonance; Surfaces and Interfaces; Thin Films; Vibration mode; SERS effect; Low-cost synthesis; DFT calculations; Copper nanoparticles
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-06531-2

Nanoparticles can enhance the intensity of susceptible vibrational modes through electromagnetic or chemical enhancement mechanisms responsible for the SERS effect (Surface-enhanced Raman spectroscopy). In the present work, copper nanoparticles (CuNP) with diameters between 3 and 10 nm were obtained by a simple method using rongalite and gelatin. The UV–Vis spectrum showed a well-defined absorption band centered at 570 nm, attributed to the surface plasmon resonance (SPR) of CuNP in a colloidal solution. The SERS effect was analyzed on the pyridine (Py) molecule, observing an enhancement in the radial breathing mode of Py. Complementarily, Cu
4n
clusters (with
n
 = 1–5) were modeled under the DFT (Density Functional Theory) framework at the B3LYP (Becke, 3-parameter, Lee–Yang–Parr) approximation level in combination with the LANL2DZ base set (Los Alamos National Laboratory 2 Double-Zeta). After analyzing the molecular descriptors, the Cu
4n
-Py interaction study provided hints of SERS behavior.