Screen-printed gold electrode with gold nanoparticles modification for simultaneous electrochemical determination of lead and copper

This paper presents a fast and sensitive approach for simultaneous electrochemical determination of lead and copper based on a commercial screen-printed gold electrode (SPGE) with gold nanoparticles (GNPs) modification. The influence of activation in sulfuric acid was discussed that the active surface area of SPGE was 1.65 times that of SPGE without activation. Deposition time for GNPs modification was optimized to be 150 s with a higher electrochemical response. Significantly enhanced electrochemical performance was observed in both cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV) compared to that of merely activated SPGE. To detect lead and copper qualitatively and quantitatively, deposition potential and deposition time were respectively optimized to be −0.5 V and 120 s. The GNPs modified SPGE presented a sensitivity of 0.154 μA/ppb and 0.084 μA/ppb towards lead and copper with a correlation coefficient of 0.9792 and 0.9896. GNPs modified SPGE revealed a wide detection range of lead from 20 ppb to 200 ppb with a limit of detection of 2.2 ppb and copper from 20 ppb to 300 ppb with a limit of detection of 1.6 ppb. Reproducibility and consistency of different GNPs modified SPGEs were investigated to verify the performance. The electrochemical behaviour of integrated pseudo-reference and counter electrode was compared with that of commercial electrodes in detail. The results exhibited a reliable approach for lead and copper detection simultaneously with high sensitivity, linearity and low limit of detection.