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Electrically ‘wired’ tyrosinase enzyme inhibition electrode for the detection of respiratory poisons
Author(s) -
Robinson Gemma,
Leech Dónal,
Smyth Malcolm R.
Publication year - 1995
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.1140071008
Subject(s) - tyrosinase , biosensor , sodium azide , chemistry , redox , azide , enzyme , glassy carbon , combinatorial chemistry , osmium , electrode , inorganic chemistry , organic chemistry , biochemistry , cyclic voltammetry , electrochemistry , catalysis , ruthenium
The use of the solution redox species, [Os(bpy) 2 Cl 2 ] +/0 , [Os(bpy) 2 (MeIm)Cl] 2+/+ and [Fe(CN) 6 ] 4−/3− , where bpy is 2,2‐bipyridine and MeIm is N ‐methylimidazole, as electron mediators in the enzymatic reduction of oxygen by tyrosinase is investigated. Co‐immobilization of both enzyme and an osmium redox mediator in a hydrogel on glassy carbon electrodes results in a biosensor for the ‘reagentless’ addressing of enzyme activity, consuming only oxygen present in solution. Immobilized enzyme inhibition biosensors can thus be constructed for the detection of tyrosinase inhibitors, such as sodium azide, using this approach. The enzyme inhibition biosensor can detect levels of azide as low as 5 × 10 −6 mol dm −3 in solution and may be useful in environmental monitoring applications and as an early warning poison sensor.