The effect of the pH on the interaction of L‐arginine with colloidal silver nanoparticles. A Raman and SERS study

Garrido, C.; Aguayo, T.; Clavijo, E.; Gómez-Jeria, Juan S.; Campos‐Vallette, Marcelo

doi:10.1002/jrs.4331

Cited by 39 publications

(29 citation statements)

References 34 publications

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“…Moreover, the wavenumbers obtained experimentally were carried out in an alkaline medium (pH 10.00), whereas the measurement of normal modes obtained from the literature was done in distilled water . On the other hand, there is evidence about a slight shift in wavenumbers between conventional Raman measurements and SERS . It should be noted that the wavenumbers found in literature for the d ‐gluconate anion are in solid state, leading to possible differences …”

Section: Resultsmentioning

confidence: 92%

Surface enhancement Raman spectroscopy and density functional theory study of silver nanoparticles synthetized with d‐glucose

Fá

López–Corral

Faccio

et al. 2018

J Raman Spectroscopy

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The role of α‐ and β‐d‐glucose, and d‐gluconate anion, acting as capping agent, on silver nanoparticles (AgNPs) was evaluated using both Raman and density functional theory studies. The particles were synthetized employing glucose, as reducing and blocking agent, in alkaline conditions. Capping agents were characterized through surface enhancement Raman spectroscopy together with modeling performed using silver clusters. Several geometries were optimized, and its energies and wavenumbers were calculated for each of them. Vibration normal modes from d‐glucose isomers and d‐gluconate were obtained and compared with those reported in bibliography, showing a satisfactory correlation. Comparison between experimental and calculated frequencies reveals a preference for d‐gluconate anion acting as capping agent under the necessary presence of d‐glucose on the surface of the AgNPs. The study of energies shows a greater affinity of d‐gluconate for the silver atoms (above −1.3 eV for both geometries) than for other configurations of the glucose molecule (about −0.66 eV in the case of α‐d‐glucose).

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Section: Resultsmentioning

confidence: 92%

Surface enhancement Raman spectroscopy and density functional theory study of silver nanoparticles synthetized with d‐glucose

Fá

López–Corral

Faccio

et al. 2018

J Raman Spectroscopy

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“…Arg (p K a = 12.5) and BPM (p K a = 9.1) were chosen as a UV probe for the indirect UV detection of memantine, amantadine, and rimantadine. These compounds were selected because of their high molar absorptivity (8 × 10 3 and 24 × 10 3 L/mol cm for Agr (50 mM) and BPM (6 mM), respectively).…”

Section: Resultsmentioning

confidence: 99%

Brompheniramine as a novel probe for indirect UV detection and its application for the capillary electrophoresis of adamantane drugs

et al. 2017

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Brompheniramine, an antihistamine drug, was employed as a novel UV probe for capillary electrophoresis with indirect UV detection of adamantane drugs (memantine, amantadine, and rimantadine). The probe possesses high molar absorptivity of 24 × 10 L/mol cm at 6 mM, which enables the measurement of these nonchromophore analytes without derivatization. The simple background electrolyte (10 mM sodium dihydrogen phosphate (pH 5.0) containing 5 mM brompheniramine and 6 mM β-cyclodextrin) provided the separation of the analytes in a short time (7.5 min). Under these conditions, brompheniramine had similar mobility to that of the analyte ions resulting in symmetric peaks with minimal electrodispersion. The analytes displace the probe at a one-to-one ratio with transfer values close to unity. β-Cyclodextrin played a role in the resolution of the structurally similar adamantane derivatives. Method validation showed good linearity (r > 0.98), precision (%RSD ≤ 3.30), and accuracy (recoveries ranging from 98 to 109%). The proposed method was successfully applied to determine the adamantane content in pharmaceutical products.

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“…It is to be noted that as the guanidinium group of Arg is positively charged at neutral and acidic pH; therefore, it would be well suited for the formation of multiple H bonds with the water molecules. However, at pH above 12, the guanidinium group could not be found in a positively charged state, and, thereby, it is not suitable for the formation of multiple H bonds. This the reason why we have considered pH values of up to 10.5 for the Raman measurements.…”

Section: Introductionmentioning

confidence: 99%

A vibrational and conformational characterization of arginine at different pH values investigated using Raman spectroscopy combined with DFT calculations

Bhunia

Srivastava

Materny

et al. 2016

J Raman Spectroscopy

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In the present study, the Raman spectra of an aqueous solution of arginine (Arg) at three different pH values (2.0, 9.0, and 10.5) were recorded in the spectral range 500-1800 cm À1 by using an excitation wavelength of 514 nm. The wavenumber position and intensity of the Raman bands lying in the spectral range 1000-1500 cm À1 changed with pH. The change in the peak parameters with pH was mainly attributed to the change of the molecular structure to zwitterionic (ZW), cationic zwitterionic (CATZW), or protonated (PRO) form. The presence of these conformers at a particular pH value is investigated by analyzing the experimental and theoretical Raman spectra. The structural, spectroscopic, and thermodynamical features of ZW, CATZW, and PRO conformers of Arg in the gas phase and the aqueous solution phase were investigated by using density functional theory (DFT) calculations at B3LYP/6-31 + G(d,p) and M062X/6-31 + G(d,p) levels of theory. The spectroscopic changes observed for the Arg-(water) 10 complex in the gas phase (explicit model) and in the bulk solvent water environment (implicit model) are explained in terms of the role that water molecules play in the stabilization or destabilization of the active sites of Arg. The structure of the most stable conformer of the ZW, CATZW, and PRO forms of Arg at the pH values of 2.0, 9.0, and 10.5 was determined by comparing the experimental and theoretical spectral features and performing a Boltzmann population analysis. The most stable conformer of Arg at a particular pH, as obtained by spectral analysis, is also well supported by the results obtained from a thermodynamical analysis.

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The effect of the pH on the interaction of L‐arginine with colloidal silver nanoparticles. A Raman and SERS study

Cited by 39 publications

References 34 publications

Surface enhancement Raman spectroscopy and density functional theory study of silver nanoparticles synthetized with d‐glucose

Surface enhancement Raman spectroscopy and density functional theory study of silver nanoparticles synthetized with d‐glucose

Brompheniramine as a novel probe for indirect UV detection and its application for the capillary electrophoresis of adamantane drugs

A vibrational and conformational characterization of arginine at different pH values investigated using Raman spectroscopy combined with DFT calculations

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