Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/55457
Type: Artigo de periódico
Title: Bi-enzymatic amperometric biosensor for oxalate
Author: Perez, EF
Neto, GD
Kubota, LT
Abstract: The development of a new amperometric biosensor for oxalate utilising two enzymes, oxalate oxidase (OXO) and horseradish peroxidase (HRP), incorporated into carbon paste electrode modified with silica gel coated with titanium oxide containing toluidine blue is described. OXO has been immobilised on silica gel modified with titanium oxide surface using glutaraldehyde for crosslinking. HRP has been immobilised with covalent binding with carbodiimide on graphite powder. The biosensor showed a good performance with a linear response range between 0.1 and 2.0 mmol 1(-1) of oxalate, fit by the equation i = 0.33(+/-0.041) + 2.29(+/-0.04) [oxalate], where i is the current in muA and [oxalate] is the oxalate concentration in mmol 1(-1) with a correlation coefficient of 0.998 for n = 20. The biosensor could be used for 80 determinations when stored in a succinate buffer at pH 3.8 in a refrigerator. The response time was about 0.5 s. The detection limit, considering three times the noise, was 0.09 mmol 1(-1) for oxalate. The time for oxalate determination in spinach samples decreased by 3 days when this biosensor was used, compared to the AOAC method. (C) 2001 Elsevier Science B.V. All rights reserved.
Subject: biosensor for oxalate
carbon paste electrode
oxalate oxidase
horseradish peroxidase
Country: Suíça
Editor: Elsevier Science Sa
Rights: fechado
Identifier DOI: 10.1016/S0925-4005(00)00637-7
Date Issue: 2001
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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