Flow injection enzyme-free amperometric uric acid sensor consisting of ordered mesoporous carbon decorated with 3D Pd-Pt alloy nanodendrite modified screen-printed carbon electrode

Abstract

A flow injection amperometric sensor for highly sensitive enzyme-free uric acid (UA) analysis was developed based on a screen-printed carbon electrode (SPCE) modified with ordered mesoporous carbon (OMC) decorated with a three-dimensional (3D) electrodeposited dendrite nanostructure of palladium-platinum (Pd-Pt) alloy. The high surface area and conductivity of OMC and the two monometallic elements of the 3D Pd-Pt alloy nanodendrite produced synergistic benefits that considerably improved electrocatalytic activity toward UA. The modified electrode provided a linear range from 0.00025 to 0.80 mM with a detection limit (LOD) of 0.25 μM (s/n ≥ 3). The sensitivity (154.45 μA mM−1 cm−2), operational stability (RSD 2.4%, 380 injections), storage stability (more than 5 weeks), and repeatability (RSD < 2.0 %, n = 6) of the electrode were all good. There was no effect from the interferences commonly found in blood. The prepared Pd-Pt/OMC/SPCE was successfully applied to measure UA in human blood serum samples with recoveries between 97 ± 4% and 102 ± 5% and the results agreed well with those of the enzymatic colorimetric assay (P > 0.05).