Electrochemical Detection of Uric Acid Based on a Carbon Paste Electrode Modified with Ta2O5 Recovered from Ore by a Novel Method

Abstract

Except for well-known commercial production procedures, this study demonstrates that Ta2O5 particles can be produced. Through a series of steps, highly pure Ta2O5 particles (99.45%) were produced from the raw ore. We have electrochemically detected one of the important nitrogenous compounds present in urine, “uric acid”, by a Ta2O5 particle-modified carbon paste electrode (Ta2O5-MCPE) using cyclic voltammetry. The prepared electrode has shown excellent current sensitivity at a pH of 6.0 phosphate-buffered solution. We have found that 4 mg Ta2O5-MCPE has recorded the highest current sensitivity of 75.75 μA. The oxidation peak current was varied with the uric acid concentration in the range from 1 to 5 mM at 4 mg Ta2O5-MCPE. We have calculated the electrode-active surface area for a bare carbon paste electrode and 4 mg Ta2O5-MCPE using the Randles-Sevcik equation, and the values were found to be 0.0202 and 0.0450 cm2, respectively. On the other hand, the calculated values of limit of detection and limit of quantification were reported as 0.5937 × 10-8 M and 1.9791 × 10-8 M, respectively, for the prepared 4 mg Ta2O5-MCPE. The interfere studies revealed that the variation in the electrochemical signal of uric acid in the presence of different metal ions was found to be less than ±5%.