Vibrational Analysis and Concentration Dependent SERS Study of Cefoperazone

Cefoperazone is a broad-spectrum antibiotic that is extremely efficient in the treatment of respiratory, abdominal, or genital infections. Vibrational spectroscopic techniques, FT-IR, Raman, and SERS, along with DFT calculations, were involved in investigating the normal modes of vibration and adsorption behavior of this antibiotic. Using both the experimental and theoretical data, the bands in the Raman and IR spectra were assigned to the normal vibrational modes. The SERS spectra were successively obtained by using silver and gold colloidal nanoparticles as a substrate. Their analysis revealed that the molecule is chemisorbed on the nanostructured surface through the as-denoted nitrogen ring. Changes observed in the SERS spectra recorded at different cefoperazone concentrations, i.e., modifications in the relative intensity of specific bands suggest the reorientation of adsorbed molecules towards the metal surface.