Selective voltammetric determination of uric acid with novel carbon electrode

摘要

The voltammetric responses of uric acid (UA) and L-ascorbic acid (L-AA) were studied with novel carbon material, plastic formed carbon (PFC) electrode. The PFC electrode resolved the overlapping voltammetric response of UA and L-AA into two well-defined voltammetric peaks in cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The differences in peak potential between UA and L-AA were more than 350 mV in 0.1 M phosphate buffer (pH 7), which enabled selective detection of UA in the presence of excess amount of L-AA. The peak height and the peak potential for oxidation of UA by DPV were changed depending on pH (from 3.0 to 9.0), and the highest response was observed at pH 6.0 at 0.31 V (vs. Ag/AgCl), The peak current of UA on DPV was linearly dependent on the UA concentration in the range from 0.5 uM to 50 uM. The detection limit was found to be 0,2 (J.M. The PFC electrode was applied to determination of UA in human urine sample by simple dilution without further complicated pretreatment. Moreover, the PFC electrode exhibited good stability and reusability.