Electrochemical Peroxidase-Catalase Clark-Type Biosensor: Computed and Experimental Response.

Kulys, Juozas; Bratkovskaja, Irina; Ašeris, Vytautas; Baronas, Romas

A bioelectrode containing immobilized catalase and peroxidase was built using a Clark-type oxygen electrode. The bioelectrode responded to hydrogen peroxide (H2O2) as well as to acetaminophen (Ac). The sensitivity of the bioelectrode for H2O2 was 0.35 mM O2/mM H2O2 and for Ac it was 0.23-1.05 µM O2/µM Ac at pH 6.6 and 25 °C. The limit of detection of Ac varied from 12 to 44 µM. The half-time of the bioelectrode response to hydrogen peroxide was 36 s. The modeling of the bioelectrode action was performed digitally at transition and steady-state conditions using finite difference technique. The calculated half-time of the bioelectrode response to hydrogen peroxide was 53 % larger and the steady-state response 11 % less than experimentally determined. The response to Ac was 2-3 times smaller in comparison to the experimental values. The calculated response change correlated with the experimentally determined when the catalase and peroxidase concentrations in the biocatalytical membrane changed 3-4 orders of magnitude. The simulations of the bioelectrode response revealed that the bioelectrode acts in diffusion limiting conditions at almost all enzymes concentrations. The model appears to be promising for optimization of the bioelectrode response.

ELECTROCHEMICAL research; CHEMISTRY; PEROXIDASE; HEMOPROTEINS; CATALASE

Electroanalysis, 2013, Vol 25, Issue 6, p1491

1040-0397

Academic Journal

10.1002/elan.201300070