A SERS investigation of antimicrobial adsorption on silver nanoparticles as mediated by surface modifiers

Abstract

In this work, the adsorptions of the antimicrobial drugs aztreonam, tinidazole and metronidazole on silver nanoparticle surfaces were investigated using surface‐enhanced Raman scattering (SERS) spectroscopy. The chemical properties of silver surface were modified by using mercaptoethanol, polyvinyl alcohol or chloride ions for changing the adsorption mechanisms, which led to distinct SERS spectral patterns. These were analyzed regarding the proximity of molecular moiety from the analyte to the silver surface. The adsorption processes were monitored by the localized surface plasmon resonance bands, which were recorded through ultraviolet‐visible spectroscopy. Theoretical models were obtained from density functional theory and used for supporting the vibrational assignments. The analyses of the SERS spectral patterns allow inferring aztreonam adsorbed through carboxylate moiety while tinidazole and metronidazole adsorbed via nitro group. The surface modifiers led to changes of the adsorption geometries of the molecules on the silver surfaces, which were rationalized based on differences in the relative intensities of the bands assigned to the out‐of‐plane modes. Copyright © 2017 John Wiley & Sons, Ltd.

Identification of erlotinib adsorption pattern onto silver nanoparticles: SERS studies

“…Conventional Raman spectroscopy method (RS) provides information about vibrational structure and composition of the investigated compound, whereas the surface‐enhanced technique (SERS) allows for understanding how the molecule interacts with the potential metal nanocarriers . Due to the fact that the spectra recorded by means of SERS technique often differ from those collected using conventional Raman scattering, the molecule–metal substrate interaction can be characterized . This phenomenon is related to the surface phenomenon and surface selection rules that govern the observed SERS spectral intensities.…”

“…[15][16][17] Due to the fact that the spectra recorded by means of SERS technique often differ from those collected using conventional Raman scattering, the molecule-metal substrate interaction can be characterized. [15][16][17][18][19][20][21][22] This phenomenon is related to the surface phenomenon and surface selection rules that govern the observed SERS spectral intensities. According to them, only this part of molecule which is adsorbed or in close proximity to the metal surface contributes to the SERS spectrum.…”

Novel Cocrystals and Eutectics of the Antiprotozoal Tinidazole: Mechanochemical Synthesis, Cocrystallization, and Characterization

“…As characteristic spectral features, the spectrum of TNZ-CA was distinct to those of TNZ and CA, in accordance with the PXRD and SSNMR data, but showed vibrational similarities with those of TNZ-PABA and TNZ-SA cocrystals. Particularly, the asymmetric NO 2 stretching vibration ,, (observed at 1522 cm –1 in pure TNZ) from the TNZ component of TNZ-CAshifted hypsochromically, like in TNZ-PABA and TNZ-SA cocrystals, and its wavenumber (1540 cm –1 ) was similar to those of TNZ-PABA (1539 cm –1 ) and TNZ-SA (1537 cm –1 ). Taking into account that, in the crystal packing of the reported crystal structure of TNZ (CSD, Refcode CEPSIZ) a tetramer is formed by C–H···O hydrogen bonds, with the C–H units forming four C–H···ON H-bonds and two bifurcated C–H···OS hydrogen bonds, the shift to a higher frequency of the asymmetric NO 2 stretching band of TNZ-CA is consistent with weak H-bonding and with the disruption of the TNZ tetramer, as observed in the crystal structures of TNZ-PABA (Figure a) and TNZ-SA (Figure a) cocrystals, thus confirming that the crystal structure of TNZ was changed in TNZ-CA.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XII

“…Filgueiras et al described a SERS investigation of antimicrobial adsorption on silver nanoparticles as mediated by surface modifiers. The surface modifiers led to changes in the adsorption geometries of the molecules on the silver surfaces, which were rationalized on the basis of differences in the relative intensities of the bands assigned to the out‐of‐plane modes . Gomes et al presented a micro‐Raman spectroscopic study of Cr(OH) 3 and Cr 2 O 3 nanoparticles obtained by the hydrothermal method.…”

“…The surface modifiers led to changes in the adsorption geometries of the molecules on the silver surfaces, which were rationalized on the basis of differences in the relative intensities of the bands assigned to the out-of-plane modes. [93] Gomes et al presented a micro-Raman spectroscopic study of Cr(OH) 3 and Cr 2 O 3 nanoparticles obtained by the hydrothermal method. Their results indicate that the as-prepared nanoparticles mainly consist of amorphous and hydrated Cr(OH) 3 , with only minor amounts of Cr 2 O 3 .…”