Polyaniline/Prussian-Blue-Based Amperometric Biosensor for Detection of Uric Acid

Polyaniline/Prussian blue (PANI-PB) composite was electrochemically deposited on a platinum electrode. The properties of the PANI-PB-modified electrode were exploited in terms of its response toward H2O2 sensing by using cyclic voltammetry, and were found to be more effectual than the PANI-modified electrode in the low-potential range. The PANI-PB-modified electrode was further used for the bioanalysis of uric acid by immobilization of the enzyme uricase. The electrode was characterized at various stages of modification by scanning electron microscopy (SEM), IR spectroscopy, and cyclic voltammetry. The biosensor gave a linear response for uric acid in the concentration range 10160M with a sensitivity of 160AmM1cm2. The main advantage of the PANI-PB composite electrode is its low working potential (0V vs. Ag/AgCl) for the estimation of uric acid, which enables the elimination of plausible interfering effects caused by analytes present in real samples. The biosensor was selective to uric acid and did not respond to analytes such as ascorbic acid, glucose, and urea. The sensor electrode retained its selectivity and sensitivity for seven days if stored at 18 degrees C. The biosensor also displayed a satisfactory performance for the detection of uric acid in human blood serum samples.