About
Contact
Help
Sending publications
How to publish
Advanced Search
View Item 
  •   Home
  • Facultad de Ciencias Químicas y Farmacéuticas
  • Artículos de revistas
  • View Item
  •   Home
  • Facultad de Ciencias Químicas y Farmacéuticas
  • Artículos de revistas
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Browse byCommunities and CollectionsDateAuthorsTitlesSubjectsThis CollectionDateAuthorsTitlesSubjects

My Account

Login to my accountRegister
Biblioteca Digital - Universidad de Chile
Revistas Chilenas
Repositorios Latinoamericanos
Tesis LatinoAmericanas
Tesis chilenas
Related linksRegistry of Open Access RepositoriesOpenDOARGoogle scholarCOREBASE
My Account
Login to my accountRegister

Scanning electrochemical microscopy (SECM) study of superoxide generation and its reactivity with 1,4-dihydropyridines

Artículo
Thumbnail
Open/Download
IconBollo_S.pdf (242.0Kb)
Publication date
2005-04-01
Metadata
Show full item record
Cómo citar
Bollo Dragnic, Soledad
Cómo citar
Scanning electrochemical microscopy (SECM) study of superoxide generation and its reactivity with 1,4-dihydropyridines
.
Copiar
Cerrar

Author
  • Bollo Dragnic, Soledad;
  • Jara Ulloa, Paola Andrea;
  • Finger Caraccioli, Sebastián;
  • Núñez Vergara, Luis;
  • Squella Serrano, Juan;
Abstract
A scanning electrochemical microscope (SECM), in the tip generation substrate collection and feedback modes, was used in a method to characterize the electrode mechanism of the O-2/O-2*(-) couple in dimethylsulphoxide (DMSO) containing 0.1 M tetrabutylammonium perchlorate (TBAP) as the supporting electrolyte. Also the quantification of the interaction between O-2*(-) and different 1,4-dihydropyridine compounds is reported. The SECM results demonstrated that the O-2/O-2*(-) couple follows an E mechanism, in contrast with the EC2 mechanism (DISPs) that was previously reported by cyclic voltammetry. This result implies that in the time scale of SECM measurements there is no time for a homogeneous chemical reaction to be coupled to the electron transfer, i.e., the superoxide is a stable radical. Also we have determined the heterogeneous standard rate constant, k(0) of the quasi-reversible reduction of oxygen to superoxide anion. Taking advantage of the fact that the superoxide suffers no chemical decay during the SECM experiment, a method to obtain the direct interaction of different 1,4-dihydropyridine molecules with superoxide was developed. The study revealed that all the 1,4-DHPs scavenged superoxide with sufficiently high interaction constants (similar to 10(5) M-1 s(-1)). No significant difference between the different molecules was found. This paper shows that the SECM feedback mode is a sensitive technique, giving an accurate determination of the homogeneous interaction constant and allowing the determination of faster rate constants than those found from cyclic voltammetry.
Identifier
URI: https://repositorio.uchile.cl/handle/2250/120405
ISSN: 0022-0728
Quote Item
JOURNAL OF ELECTROANALYTICAL CHEMISTRY 577 (2): 235-242 APR 1 2005
Collections
  • Artículos de revistas
xmlui.footer.title
31 participating institutions
More than 73,000 publications
More than 110,000 topics
More than 75,000 authors
Published in the repository
  • How to publish
  • Definitions
  • Copyright
  • Frequent questions
Documents
  • Dating Guide
  • Thesis authorization
  • Document authorization
  • How to prepare a thesis (PDF)
Services
  • Digital library
  • Chilean academic journals portal
  • Latin American Repository Network
  • Latin American theses
  • Chilean theses
Dirección de Servicios de Información y Bibliotecas (SISIB)
Universidad de Chile

© 2020 DSpace
  • Access my account