Voltammetric behaviour of a modified electrode with azide copper octa(3-aminopropyl)octasilsesquioxane composite in the oxidation of ascorbic acid

A novel nanostructured composite, azide copper octa (3-aminopropyl)octasilsesquioxane (ASCA) was incorporated into a graphite paste electrode and the electrochemical studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with ASCA (GPE-ASCA),...

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Detalhes bibliográficos
Autores: Carmo, Devaney Ribeiro do [UNESP], Paim, Leonardo Lataro [UNESP], Silvestrini, Daniela Rodrigues [UNESP], Sá, Acelino Cardoso de [UNESP], Bicalho, Urquisa de Oliveira [UNESP], Stradiotto, Nelson Ramos [UNESP]
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2011
País:Brasil
Recursos:Universidade Estadual Paulista (UNESP)
Repositório:Repositório Institucional da UNESP
Idioma:inglês
OAI Identifier:oai:repositorio.unesp.br:11449/123542
Acesso em linha:http://www.electrochemsci.org/list11.htm
http://hdl.handle.net/11449/123542
Access Level:Acceso aberto
Palavra-chave:Silsesquioxane
ascorbic acid
graphite paste electrode
voltammetry
modified electrode
Descrição
Resumo:A novel nanostructured composite, azide copper octa (3-aminopropyl)octasilsesquioxane (ASCA) was incorporated into a graphite paste electrode and the electrochemical studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with ASCA (GPE-ASCA), showed one redox couple with formal potential (E  ) = 0.30 V and an irreversible process at 1.1 V (vs Ag/AgCl; NaCl 1.0 mol L-1 ; v = 20 mV s-1 ). The redox couple with (E  ) = 0.30V presents an electrocatalytic response for determination of ascorbic acid. The modified electrode gives a linear range from 1.010-4 – 1.010-3 mol L-1 (r = 0.998) for the determination of ascorbic acid with detection limit of 6.910-5 mol L-1 and standard deviation of 2.3% for n = 3 . The amperometric sensitivity was 122.1 mA/mol L-1 for ascorbic acid. The application this electrode was tested and ascorbic acid in three commercial pharmaceutical product (Cebion, Cewin and Redoxon) have been determined.