A selective voltammetric method for uric acid detection at a glassy carbon electrode modified with electrodeposited film containing DNA and Pt-Fe(III) nanocomposites

摘要

A novel biosensor by electrochemical codeposited Pt-Fe(III) nanocomposites and DNA film was constructed and applied to the detection of uric acid (UA) in the presence of high concentration of ascorbic acid (AA). Based on its strong catalytic activity toward the oxidation of UA and AA, the modified electrode resolved the overlapping voltammetric response of UA and AA into two well-defined peaks with a large anodic peak difference (DeltaE(pa)) Of about 380mV. The catalytic peak current obtained from differential pulse voltammetry (DPV) was linearly dependent on the UA concentration from 3.8 x 10(-6) to 1.6 x 10(-4) M (r = 0.9967) with coexistence of 5.0 x 10(-4) M AA. The detection limit was 1.8 x 10(-6) M (S/N= 3) and the presence of 20 times higher concentration of AA did not interfere with the determination. The modified electrode shows good sensitivity, selectivity and stability.