Oxidation and flow-injection amperometric determination of 5-hydroxytryptophan at an electrode modified by electrochemically assisted deposition of a sol-gel film with templated nanoscale pores.
Talanta
; 82(4): 1149-55, 2010 Sep 15.
Article
en En
| MEDLINE
| ID: mdl-20801311
ABSTRACT
The oxidation of 5-hydroxytryptophan (5-HTPP) yielded a passivating polymeric film at an indium tin oxide (ITO) electrode. Coating ITO with a nanoscale sol-gel film with a mesoporous structure was shown to change the pathway of the chemical reaction coupled to the electron transfer. The sol-gel film was deposited by an electrochemically assisted process, and the mesoporosity was imparted by including generation-4 poly(amidoamine) dendrimer in the precursor solution. The dendrimer was removed subsequently with an atmospheric oxygen plasma. This electrode remained active during cyclic voltammetry and controlled potential electrolysis of 5-HTPP, which was attributed to dimer, rather than polymer, formation from the oxidation product. Mass spectrometry confirmed this hypothesis. The anodic current was limited by the electron-transfer kinetics. Modification of the sol-gel film by inclusion of cobalt hexacyanoferrate, which catalyzes the oxidation, resulted in a diffusion-limited current. Determination of 5-HTPP by flow-injection amperometry had a detection limit of 17nM.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
5-Hidroxitriptófano
/
Análisis de Inyección de Flujo
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Nanotecnología
/
Electrodos
Idioma:
En
Revista:
Talanta
Año:
2010
Tipo del documento:
Article
País de afiliación:
Estados Unidos