Artículos de revistas
Urea amperometric biosensors based on a multifunctional bipolymeric layer: Comparing enzyme immobilization methods
Fecha
2009Registro en:
SENSORS AND ACTUATORS B-CHEMICAL, v.137, n.2, p.476-482, 2009
0925-4005
10.1016/j.snb.2009.02.013
Autor
MASSAFERA, Mariana P.
TORRESI, Susana I. Cordoba de
Institución
Resumen
This paper outlines the results obtained with biosensors designed for urea amperometric detection. The incorporation of urease into a bipolymeric substrate consisting of poly(pyrrole) and poly(5-amino-1-naphthol) was performed through four different approaches: direct adsorption, entrapment in cellulose acetate layer. cross-linking with glutaraldehyde, and also covalent attachment to the polymeric matrix. Poly(pyrrole) acts as amperometric transducer in these biosensors, while poly(5-amino-1-naphthol) drastically reduces the interference signal of agents such as ascorbic and uric acids. The biosensors containing urease covalently attached to the substrate provided interesting results in terms of sensitivity towards urea (0.50 mu A cm(-2) mmol(-1) L), lifetime (20 days) and short response times, due to the enzyme immobilization method used. All biosensors analyzed showed also a wide linear concentration range (up to 100 mmol L(-1)) and low detection limits (0.22-0.58 mmol L(-1)). (C) 2009 Elsevier B.V. All rights reserved.