Lactate Dehydrogenase Biosensor Based on an Hybrid Carbon Nanotube-Conducting Polymer Modified Electrode

Agui, L.; Eguílaz M.; Pena-Farfal, C; Yanez-Sedeno, P; Pingarron, JM

Abstract

A lactate biosensor constructed by immobilization of the enzyme lactate dehydrogenase (LDH) on a glassy carbon electrode modified with a hybrid material composed of the conducting polymer poly (3-methylthiophene) (P3 MT), electrodeposited on the electrode surface, and multiwalled carbon nanotubes (MWCNTs), is reported. The excellent characteristics of the electrode modified with the hybrid material toward the electrochemical oxidation of NADH allowed the construction of a robust LDH electrochemical biosensor able to operate at a working potential as low as + 300 mV without the need for redox mediator. Experimental variables affecting the performance of the biosensor: amount of LDH immobilized on the modified electrode surface, buffer composition and working pH value, MWCNTs loading in the hybrid material and NAD+ concentration were optimized. Under the optimized conditions, a linear calibration graph for lactate was obtained over the 1.0 × 10-6 - 5.0 × 10 -4 M(r=0.9993) concentration range, with a detection limit of 5.6 10-7 M. The biosensor design showed good repeatability of the measurements, good reproducibility in the inter-biosensor assays and a good selectivity against other organic acids, especially when the biosensor is coated with a Nafion film. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Más información

Título según WOS: Lactate Dehydrogenase Biosensor Based on an Hybrid Carbon Nanotube-Conducting Polymer Modified Electrode
Título según SCOPUS: Lactate dehydrogenase biosensor based on an hybrid carbon nanotube-conducting polymer modified electrode
Título de la Revista: ELECTROANALYSIS
Volumen: 21
Número: 03-may
Editorial: WILEY-V C H VERLAG GMBH
Fecha de publicación: 2009
Página de inicio: 386
Página final: 391
Idioma: English
URL: http://doi.wiley.com/10.1002/elan.200804404
DOI:

10.1002/elan.200804404

Notas: ISI, SCOPUS - ISI