Amperometric biosensor for glutamate using Prussian Blue-based "artificialperoxldase" as a transducer for hydrogen peroxide

The specially deposited Prussian Blue denoted as "artificial peroxidase" wa s used as a transducer for hydrogen peroxide, The electrocatalyst as stable , highly active, and selective to hydrogen peroxide reduction in the presen ce of oxygen, which allowed sensing of H2O2 around 0.0 V (Ag/AgCl). Glutama te oxidase was immobilized on the surface of the Prussian Blue-modified ele ctrode in a Nafion layer using a nonaqueous enzymology approach. The calibr ation range for glutamate in flow injection system was 1 x 10(-7)-1 x 10(-4 ) M. The lowest concentration of glutamate detected (1 x 10(-7) M) and the highest sensitivity in the linear range of 0.21 A M-1 cm(-2) were achieved. The influence of reductants was practically avoided using the low potentia l of an indicator electrode (0.0 V Ag/AgCl). The attractive performance cha racteristics of the glutamate biosensor illustrate the advantages of Prussi an Blue-based "artificial peroxidase" as transducer for hydrogen peroxide d etection.