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Development of an Amperometric Biosensor for β‐ N ‐Oxalyl‐ L ‐α,β‐Diaminopropionic Acid (β‐ODAP)
Author(s) -
Beyene Negussie W.,
Moderegger Helmut,
Kalcher Kurt
Publication year - 2004
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.200302825
Subject(s) - amperometry , biosensor , analyte , detection limit , flow injection analysis , electrode , chromatography , nafion , chemistry , buffer solution , working electrode , analytical chemistry (journal) , nuclear chemistry , electrochemistry , biochemistry
An amperometric method for the determination of the neurotoxic amino acid β‐ N ‐oxalyl‐ L ‐α,β‐diaminopropionic acid (β‐ODAP) using a screen printed carbon electrode (SPCE) is reported. The electrode material was bulk‐modified with manganese dioxide and used as a detector in flow injection analysis (FIA). The enzyme glutamate oxidase (GlOx) was immobilized in a Nafion‐film on the electrode surface. The performance of the biosensor was optimized using glutamate as an analyte. Optimum parameters were found as: operational potential 440 mV (vs. Ag/AgCl), flow rate 0.2 mL min −1 , and carrier composition 0.1 mol L −1 phosphate buffer (pH 7.75). The same conditions were used for the determination of β‐ODAP. The signal was linear within the concentration range 53–855 μmol L −1 glutamate and 195–1950 μmol L −1 β‐ODAP. Detection limits (as 3σ value) for both analytes were 9.12 and 111.0 μmol L −1 , respectively, with corresponding relative standard deviations of 3.3 and 4.5%. The biosensor retained more than 73% of its activity after 40 days of on‐line use.