Glucose sensitivity of polypyrrole-glucose oxidase modified electrodes containing p-benzoquinone in biological buffer

The entrapping of enzymes in a polypyrrole (PPy) matrix during electropolimerization is attacting great interest as an immobilization technique, because it is simple and speady for the production of biosensors. PPy/Glucose oxidase (GOD) modified electrodes, which catalyse the oxidation of glucose to gluconolactone are prepared by the electropolimerization of pyrrole from a solution containing GOD in the presence of p.benzoquinone (Q).Q acts as a mediator for the electron transfer between GOD and the electrode. The phosphate buffer which is generally used is very nucleophilic and prevents a homogeneous growth of PPy films, therefore, it has been replaced by PIPES buffer (pk_a=6.8). GOD and Q are incorporated into polypyrrole films and provide electrical communications. Glucose sensitivity depends on the deposition charge of polymer films and there is an optimum deposition charge. Moreover, in this study, the response curves were kinetically analyzed and apparent Michaelis constants (K_m) and apparent maximum rate(I_max) were determined.