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Development of a Carbon Paste Electrode for Lactate Detection Based on Meldola’s Blue Adsorbed on Silica Gel Modified with Niobium Oxide and Lactate Oxidase
Author(s) -
Pereira Arnaldo C.,
Kisner Alexandre,
Tarley César R. T.,
Kubota Lauro T.
Publication year - 2011
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201000709
Subject(s) - biosensor , adsorption , chemistry , amperometry , carbon paste electrode , chromatography , electrode , ionic strength , nuclear chemistry , glucose oxidase , inorganic chemistry , electrochemistry , organic chemistry , cyclic voltammetry , biochemistry , aqueous solution
A reagentless amperometric biosensor sensitive to lactate was developed. The sensor employs a carbon paste electrode modified with lactate oxidase (LOx) and Meldola’s Blue (MB) adsorbed on silica gel coated with niobium oxide. The dependence on the biosensor response was investigated in terms of pH, supporting electrolyte, ionic strength, lactate oxidase (LOx) amounts and applied potential. The biosensor showed an excellent operational stability (96 % of the activity was maintained after 150 determinations) and storage stability (allowing measurements for more than 1.5 months, when stored in a refrigerator). The proposed biosensor also presented good sensitivity allowing lactate quantification at levels down to 6.5×10 −7 mol L −1 . Moreover, the biosensor showed a good linear response range (from 0.1 to 5.0 mmol L −1 for lactate). Lactate analysis in biological samples such as blood was also performed. The precision of the data obtained by the proposed biosensor showed reliable results for real complex matrices.