Direct electrochemistry and spectroelectrochemistry of osmium substituted horseradish peroxidase.
Bioelectrochemistry
; 76(1-2): 28-33, 2009 Sep.
Article
em En
| MEDLINE
| ID: mdl-19411193
ABSTRACT
In this contribution the substitution of the central protoporphyrin IX iron complex of horseradish peroxidase by the respective osmium porphyrin complex is described. The direct electrochemical reduction of the Os containing horseradish peroxidase (OsHRP) was achieved at ITO and modified glassy carbon electrodes and in combination with spectroscopy revealed the three redox couples Os(III)HRP/Os(IV)HRP, Os(IV)HRP/Os(V)HRP and Os(V)HRP/Os(VI)HRP. The midpoint potentials differ dependent on the electrode material used with E(1/2) (Os(III/IV)) of -0.4 V (ITO) and -0.25 V (GC), E(1/2) (Os(IV)/(V)) of -0.16 V (ITO) and +0.10 V (GC), and E(1/2) (Os(V/VI))of +0.18 V (ITO), respectively. Moreover, with immobilised OsHRP the direct electrocatalytic reduction of hydrogen peroxide and tert-butyl hydroperoxide was observed. In comparison to electrodes modified with native HRP the sensitivity of the OsHRP-electrode for tert-butyl hydroperoxide is higher.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Osmio
/
Peroxidase do Rábano Silvestre
Idioma:
En
Revista:
Bioelectrochemistry
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Alemanha