A POLYPYRROLE 3-ENZYME ELECTRODE FOR CREATININE DETECTION

To detect creatinine, an enzyme electrode was made by co-immobilizatio n of three enzymes, creatininase, creatinase, and sarcosine oxidase, i n an active polypyrrole (PPy) matrix. Besides platinum, polypyrrole do ped with a sulfated phenoxy resin (S-PHE) was used as a base electrode . The device was fabricated by electropolymerization of pyrrole in the presence of water soluble polyanions, enzymes, and a phosphate buffer , using the above-mentioned base electrodes. At a potential of 400 mV vs Ag/AgCl, the sensors responded to creatinine with a sufficient sens itivity. Under a nitrogen atmosphere, the response current was higher when PPy/S-PHE was used as a base electrode. As a main transduction pa thway, a direct electron transfer from sarcosine oxidase to PPy chains is discussed. In addition, the influences of the different polyanioni c dopants, the thickness of the active layer, and the concentration of sarcosine oxidase in preparation solutions on the sensor's performanc e were examined.