Biosensor for Uric Acid Determination Based on Combination of Polypyrrole and Poly(allylamine) Films

Aim and Background: The use of polypyrrole and poly(allylamine) as a matrix of biosensor has been done separately, but the combination of this two has never existed. The purpose of this research is to produce a selective biosensor using combination of polypyrrole (PPy) and poly(allylamine) (PAA) as a polymer for the immobilization of the uricase enzyme, which is used to detect uric acid level in the blood. Materials and Methods: Biosensor manufacturing process began with the electropolimerization of pyrrole on platinum wire then immobilization r turicase enzyme (UOx) with glutaraldehyde as cross-linker, After that, UOx and PAA were deposited via layer-by-layer sequential deposition up to 10 UOx layers to prepare amperometric sensors for uric acid. Biosensor proved to have a linear relationship between the current response and the increase of analyte concentrations, with a correlation coeffi cient (r) = 0.992. Results and Conclusion: Presence of interferences had a little effect on uric acid analysis i.e. 1.39% glucose and1.65% ascorbic acid. The sensors could be used up to 32 times. In the stability test, 13.4% of the initial amperometric response decreased at day 33^rd. The results showed that combination of PPy and PAA can be used as a matrix for uric acid biosensor.

Key words: Biosensor, uric acid, polypyrrole, poly (allylamine).