Evaluation of different strategies for the development of amperometric biosensors for L-lactate.
Biosens Bioelectron
; 22(11): 2663-8, 2007 May 15.
Article
em En
| MEDLINE
| ID: mdl-17141496
ABSTRACT
Two strategies were investigated for the development of lactate biosensors based on sol-gel matrixes and polysulfone composite films, both containing L-lactate dehydrogenase (LDH). Firstly, reagentless disposable screen-printed electrodes (SPE's) with Meldola's Blue (MB) and the cofactor NAD(+) inside a sol-gel matrix were prepared. These showed relatively low sensitivities (260 microA/M). Secondly, mediator-modified-polysulfone-graphite composite films deposited over both cylindrical epoxy-graphite and SPE's. These electrodes showed enhanced performance characteristics improved sensitivity (80 mA/M), detection limit (0.87 microM) and reproducibility (2%). Reagentless electrodes, incorporating NAD(+) in the polysulfone film, had a decreased sensitivity, although better than that achieved by the sol-gel electrodes. While sol-gel electrodes showed a linear range between 1.25 x 10(-4) and 2.48 x 10(-3)M, the epoxy-graphite composite electrodes based on polysulfone composite films allowed the detection of lactate at a linear range of lower concentrations from 1 x 10(-6) to 1.2 x 10(-5)M. Finally, the performance of the LDH-MB-polysulfone-composite film-based SPE's in a flow system was studied. Short response times were obtained (t<30s). Furthermore, repeatability and reproducibility values were notably improved, especially when working with electrodes covered with a polyamide layer prepared with N-(2-aminoethyl)-piperazine.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polímeros
/
Sulfonas
/
Técnicas Biossensoriais
/
Ácido Láctico
/
Eletroquímica
/
L-Lactato Desidrogenase
/
Microeletrodos
Tipo de estudo:
Diagnostic_studies
/
Evaluation_studies
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article