CYCLIC VOLTAMMETRY AND SHORT-TIME SCALE CHRONOAMPEROMETRY AT LAYER-BY-LAYER SELF-ASSEMBLED Au MODIFIED ELECTRODES. FRUCTOSE BIOSENSOR

Abstract

Cyclic voltammetry (CV) and short-time scale chronoamperometry measurements were performed aiming to investigate the layer-by-layer self-assembled multilayer structures built on Au electrodes. The attractive electrostatic interactions exerted between the successively deposited layers of charged polymers were exploited in order to immobilize a cationic Os redox polymer onto the surface of Au modified electrodes. CV responses observed at the resulted Au modified electrodes proved the efficiency of the proposed design. The chronoamperometric responses were fitted by using a three-phase exponential decay function. The fitting parameters allowed comparing the ability of charge transfer of the investigated modified electrodes. The most efficient structure was used as an amperometric transducer for electrical communication between fructose dehydrogenase and the Au electrode. In order to validate the new approach as a proof of concept for obtaining reagentless biosensors, a functional amperometric biosensor for D-fructose was successfully built.