Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide
Autor(a) principal: | |
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Data de Publicação: | 2002 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532002000400014 |
Resumo: | The electrochemical behavior of toluidine blue (TB) adsorbed on a silica surface modified with niobium oxide (SN) was investigated using a modified carbon paste electrode. The presence of SN gave the electrode high stability, avoiding the leaching out of the mediator from the electrode surface. The formal potential (E0') of the adsorbed TB was --113 mV vs. SCE, indicating a shift of almost 100 mV towards more positive potential values, compared to TB dissolved in aqueous solution or adsorbed on carbon paste. The stability and formal potential remained constant upon changing the solution pH in the range 5 to 8. In these solution pH values the electrocatalytic activity remained almost constant with a sensitivity of 1.2 10-4 A L mol-1 cm-2 and a K Mapp of 4.9 10-5 mol L-1. A linear response range for NADH concentration between 2.0 10-4 and 4.0 10-3 mol L-1 at pH 7.0, with a detection limit of 3.4 10-5 mol L-1 was observed for the sensor. A response time of 2 s and a precision of 1.0 %, expressed as relative standard deviation for 10 replicates, were observed for the sensor developed. |
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Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxidetoluidine blueniobium oxide modified silicamodified electrodeNADHamperometric detectionThe electrochemical behavior of toluidine blue (TB) adsorbed on a silica surface modified with niobium oxide (SN) was investigated using a modified carbon paste electrode. The presence of SN gave the electrode high stability, avoiding the leaching out of the mediator from the electrode surface. The formal potential (E0') of the adsorbed TB was --113 mV vs. SCE, indicating a shift of almost 100 mV towards more positive potential values, compared to TB dissolved in aqueous solution or adsorbed on carbon paste. The stability and formal potential remained constant upon changing the solution pH in the range 5 to 8. In these solution pH values the electrocatalytic activity remained almost constant with a sensitivity of 1.2 10-4 A L mol-1 cm-2 and a K Mapp of 4.9 10-5 mol L-1. A linear response range for NADH concentration between 2.0 10-4 and 4.0 10-3 mol L-1 at pH 7.0, with a detection limit of 3.4 10-5 mol L-1 was observed for the sensor. A response time of 2 s and a precision of 1.0 %, expressed as relative standard deviation for 10 replicates, were observed for the sensor developed.Sociedade Brasileira de Química2002-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532002000400014Journal of the Brazilian Chemical Society v.13 n.4 2002reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532002000400014info:eu-repo/semantics/openAccessSantos,Antonio S.Pereira,Arnaldo C.Kubota,Lauro T.eng2002-09-06T00:00:00Zoai:scielo:S0103-50532002000400014Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2002-09-06T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
title |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
spellingShingle |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide Santos,Antonio S. toluidine blue niobium oxide modified silica modified electrode NADH amperometric detection |
title_short |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
title_full |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
title_fullStr |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
title_full_unstemmed |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
title_sort |
Electrochemical and electrocatalytic studies of toluidine blue immobilized on a silica gel surface coated with niobium oxide |
author |
Santos,Antonio S. |
author_facet |
Santos,Antonio S. Pereira,Arnaldo C. Kubota,Lauro T. |
author_role |
author |
author2 |
Pereira,Arnaldo C. Kubota,Lauro T. |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Santos,Antonio S. Pereira,Arnaldo C. Kubota,Lauro T. |
dc.subject.por.fl_str_mv |
toluidine blue niobium oxide modified silica modified electrode NADH amperometric detection |
topic |
toluidine blue niobium oxide modified silica modified electrode NADH amperometric detection |
description |
The electrochemical behavior of toluidine blue (TB) adsorbed on a silica surface modified with niobium oxide (SN) was investigated using a modified carbon paste electrode. The presence of SN gave the electrode high stability, avoiding the leaching out of the mediator from the electrode surface. The formal potential (E0') of the adsorbed TB was --113 mV vs. SCE, indicating a shift of almost 100 mV towards more positive potential values, compared to TB dissolved in aqueous solution or adsorbed on carbon paste. The stability and formal potential remained constant upon changing the solution pH in the range 5 to 8. In these solution pH values the electrocatalytic activity remained almost constant with a sensitivity of 1.2 10-4 A L mol-1 cm-2 and a K Mapp of 4.9 10-5 mol L-1. A linear response range for NADH concentration between 2.0 10-4 and 4.0 10-3 mol L-1 at pH 7.0, with a detection limit of 3.4 10-5 mol L-1 was observed for the sensor. A response time of 2 s and a precision of 1.0 %, expressed as relative standard deviation for 10 replicates, were observed for the sensor developed. |
publishDate |
2002 |
dc.date.none.fl_str_mv |
2002-08-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532002000400014 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532002000400014 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532002000400014 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.13 n.4 2002 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318164921548800 |