ISSN:
1040-0397
Keywords:
NADH
;
Ethylenimine
;
Redox polymers
;
Biosensors
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The electrocatalytic oxidation of nicotinamide adenine dinucleotide (NADH) by two redox polymers was evaluated from steady-state measurements at drop-coated solid graphite electrodes in 0.25 M phosphate buffer, pH 7.0, at 0 mV (vs. SCE). The redox polymers studied comprised a styrene polymer incorporating positive charges through quaternary amines and Toluidine Blue 0 (TBO) moieties (ST) and a branched polyethylenimine with part of its primary amine groups loaded with TBO (PE). The catalytic efficiencyjudged from the maximum NADH sensitivity for the PE polymer was estimated to be 230 μa cm.-2 mM-1 at a coverage of 40 μgcm-2 and for the ST polymer 300 μAcm-2 cmM-1 at about 100 μg cm-2. Reagentless biosensors sensing D-glucose and L-malate were constructed from bulk modified carbon paste containing the PE redox polymer, NAD+, polyethylenimine (PEI) and D-glucose dehydrogenase or L-malate dehydrogenase. The D-glucose and L-malate sensors were characterized in a flow injection system by apparent j′max- and K′M-values of 230 μA cm-2 and 62mM and 3.3 μAcm-2 and 1.7mM, respectively. It was shown for glucose dehydrogenase that the presence of PEI in the paste in addition to the PE polymer, drastically improved the enzymatic conversion of glucose to gluconic acid.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140080614
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