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Mytilus edulis Adhesive Protein (MAP) as an Enzyme Immobilization Matrix in the Fabrication of Enzyme‐Based Electrodes
Author(s) -
Saby Coralie,
Luong John H. T.
Publication year - 1998
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/(sici)1521-4109(199811)10:17<1193::aid-elan1193>3.0.co;2-c
Subject(s) - glucose oxidase , electrode , glassy carbon , chemistry , buffer solution , nuclear chemistry , electrochemistry , chromatography , cyclic voltammetry
A simple enzyme immobilization technique using an adhesive protein isolated from Mytilus edulis blue mussels was optimized for constructing a glucose oxidase (GOD) based electrode. Owing to the presence of 10–15 % of 3,4‐dihydroxyphenylalanine residues, the mussel adhesive protein (MAP) was easily oxidized to form a stable protein film on platinum, gold and glassy carbon electrodes. Covalent attachment of glucose oxidase to adhesive protein modified electrodes was attained since the oxidized form of the L ‐Dopa moieties was very reactive towards various compounds containing amino, alcohol and thiol groups. Glucose detection was performed using MAP/GOD modified electrodes at +0.8 V in 0.1 M phosphate buffer, pH 5. Platinum modified electrodes (Pt/MAP/GOD) exhibited a considerably higher sensitivity (1.28 μA/mM) in comparison to its gold (Au/MAP/GOD, 2.92 nA/mM) or glassy carbon (GC/MAP/GOD, 2.62 nA/mM) counterparts. Tetrachloro‐1,4‐benzoquinone (TCBQ), an oxidation product of pentachlorophenol, was detected using MAP/GOD modified electrodes at +0.45 V in a deaerated 0.1 M tartaric acid buffer, pH 3.5 containing 40 mM glucose. In steady state, the current response of the Au/MAP/GOD electrode was higher (6.62 nA nM −1 cm −2 , t 95 = 83 s, 5 nM) than the GC/MAP/GOD electrode (3.78 nA nM −1 cm −2 , 8 nM). In flow injection analysis, GC/MAP/GOD electrodes exhibited a linear response for TCBQ ranging from 10 nM to 1 μM (3.96 nAs nM −1 ) with a detection limit of 10 nM. The modified glassy carbon enzyme based electrode retained 90 % and 87 % of its activity after 150 and 250 repeated injections.