Kinetic approach for the study of noncovalent interaction between [Ru(NH3)5pz]2+ and gold nanoparticles.
J Phys Chem A
; 111(39): 9769-74, 2007 Oct 04.
Article
em En
| MEDLINE
| ID: mdl-17850050
ABSTRACT
Gold nanoparticles (AuNPs) capped with N-(2-mercaptopropionyl)glycine have been used to study the strength and character of the binding of a cationic metal complex, [Ru(NH3)5pz]2+ (pz = pyrazine), at pH = 8, to these nanoparticles. The strength of the binding has been studied using a kinetic approach consisting of the study of the kinetics of the oxidation of this ruthenium complex by S2O82- at different NaCl concentrations. When the ionic strength increases, the strength of the binding decreases, as a consequence of the partial neutralization of the charge on the AuNPs which, at pH = 8, has the tiopronin residue negatively charged. The increase of the ionic strength also produces a change in the character of the binding, which changes from anticooperative to noncooperative when the ionic strength increases. The nonelectrostatic and electrostatic components of the free energy of binding are determined. From the latter, we have obtained the values of the electrostatic potential differences at the AuNPs/solutions interface.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Rutênio
/
Nanopartículas Metálicas
/
Ouro
/
Tiopronina
Idioma:
En
Revista:
J Phys Chem A
Assunto da revista:
QUIMICA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Espanha