Amperometric glucose sensors based on ferrocene-containing B-polyethylenimine and immobilized glucose oxidase

In this study the preparation and performance of amperometric enzyme electrodes are described. Two types of electrodes were used in this study, a carbon paste electrode and a graphite rod electrode. Both of the electrodes incorporated glucose oxidase and ferrocene-containing branched polyethylenimine (B-PEI). B-PEI contains a high concentration of primary amino groups and can easily be modified to generate facile enzyme and mediator carriers. An additional advantage of B-PEI is the flexible nature of its backbone, which is important for efficient electron mediation. These electrodes are modified with a hydrophilic polymer matrix of glucose oxidase covalently bound to the B-PEI polymer containing ferrocene moieties. Experiments using cyclic voltammetry and constant applied potential have shown that these electrodes with ferrocene-containing B-PEI and glucose oxidase respond rapidly to a wide range of glucose concentrations, with steady state current responses achieved in less than 10s.