Improved anodic stripping voltammetric detection of zinc on a disposable screen-printed gold electrode

Herein, we report the improved detection of Zn2+ via square-wave anodic stripping voltammetry utilizing an electrochemically treated screen-printed gold electrode. Surface analysis of the gold surface revealed increase in rugosity, removal of residual polymeric ink, and consequent higher access to gold microparticles after electrochemical treatment which resulted in improved response for Zn2+ (detection limit of 2.5 mu g L- 1). The intra- and inter-electrode precision values were calculated as 3% (n = 10) and 12.5% (n = 3), respectively, applying - 0.9 V for 90 s under stirring of 1000 rpm for pre-concentration of Zn2+ (step potential: 4 mV; amplitude: 50 mV, frequency: 50 Hz) in 0.04 mol L- 1 Britton-Robinson buffer (pH 7.0) as the background electrolyte. Satisfactory recovery values ranging 96 to 104% were achieved for the analysis of struvite (spiked sample). Therefore, the proposed sensor provides precise and accurate direct analyses, without interference from other metals, with rapid responses enabling on-site analyses.