Characterisation of a thermophilic L-glutamate dehydrogenase biosensor for amperometric determination of L-glutamate by flow injection analysis.
Carbon paste wax electrodes incorporating thermophilic L-glutamate dehydrogenase, NADP and a polymeric toluidine blue O (poly-TBO) mediator have been characterised for the amperometric determination of L-glutamate at 313-318 K in a flow injection analysis (FIA) system. The biosensors exhibit good sensitivity, mechanical stability and reproducibilty, unlike carbon paste- or carbon wax-based electrodes under the same conditions. The carbon paste wax electrode responds linearly to L-glutamate up to 40 mM, the detection limit is 0.3 mM and the RSD (n = 10) for 5 mM L-glutamate was 7.6%. The response to some potential interferents has been quantified. Addition of finely ground hexaammineruthenium (III) trichloride ([Ru(NH3)6]Cl3) to the carbon paste wax electrodes decreases the FIA peak width and increases the peak current. The metal complex appears to accelerate the rate of oxidation of NAD(P)H by poly-TBO.
Pasco
N
N
Lincoln Technology, Lincoln Ventures Limited, Lincoln University, Canterbury, New Zealand.
Jeffries
C
C
Davies
Q
Q
Downard
A J
AJ
Roddick-Lanzilotta
A D
AD
Gorton
L
L
D015374:Biosensing Techniques; D004563:Electrochemistry; D004566:Electrodes; D017022:Flow Injection Analysis; D005969:Glutamate Dehydrogenase; D018698:Glutamic Acid / Q000032:analysis*
D018698:Glutamic Acid; D005969:Glutamate Dehydrogenase