Electrodeposited nonconducting polytyramine for the development of glucose biosensors

Biosensors with the composition of carbon/Prussian blue/(glucose oxidase + glutaraldehyde + polytyramine) were constructed. Before tyramine monomers were electropolymerized, glucose oxidase and tyramine monomers were cross-linked with glutaraldehyde onto the surface of Prussian-blue-modified electrodes. The constructed biosensors produced highly reproducible and stable devices. The biosensors exhibited neglectable decrease in current response after 10 repeated uses or after 1 month of dry storage. The resultant biosensors had a linear range of 0.1-1 mM glucose and a detection limit of 0.05 mM. Since the following electrocatalytic process proceeds at a low electrode potential (ca. −0.3 V vs Ag/AgCl), ascorbate and uric acid do not produce observable interfering signal for the determination of glucose.