info:eu-repo/semantics/article
Amperometric biosensor for direct blood lactate detection
Fecha
2010-07Registro en:
Romero, Marcelo Ricardo; Ahumada, Facundo; Garay, Fernando Sebastian; Baruzzi, Ana Maria; Amperometric biosensor for direct blood lactate detection; American Chemical Society; Analytical Chemistry; 82; 13; 7-2010; 5568-5572
0003-2700
CONICET Digital
CONICET
Autor
Romero, Marcelo Ricardo
Ahumada, Facundo
Garay, Fernando Sebastian
Baruzzi, Ana Maria
Resumen
An amperometric sensor for lactate quantification is presented. The developed biosensor requires only 0.2 U of lactate oxidase, which is immobilized in a mucin/albumin hydrogel matrix. By protecting the platinum surface with a Nafion membrane, typical interference related to negatively charged species such as ascorbic acid has been minimized to practically undetectable levels. Electrochemical properties associated with the Nafion membrane are assessed as a function of Nafion concentration. In a phosphate buffer solution of pH 7.0, linear dependence of the catalytic current upon lactate bulk concentration was obtained between 2 and ∼1000 μM. A detection limit of 0.8 μM can be calculated considering 3 times the standard deviation of the blank signal divided by the sensitivity of the sensor. The lactate biosensor presents remarkable operational stability and sensitivity (0.537 ± 0.007) mA.M-1, where the error is the standard deviation of the slope calculated from the linear regression of the calibration curve of a fresh biosensor. In this regard, the sensor keeps practically the same sensitivity for 5 months, while the linear range decreases until an upper value of 0.8 mM is reached. Assays performed with whole blood samples spiked with 100 μM lactate gave (89 ± 6)% of recovery. © 2010 American Chemical Society.