Effect of the working and counter/quasi-reference electrode relative area ratio of silver sensor electrodes on voltammetric detection of Pb(II)

The electrochemical properties of the voltammetric Pb(II) sensor were investigated by considering the influence of the relative geometric area ratio (working electrode: counter/quasi-reference electrode = 3.20 (R3), 10.45 (R10), and 22.13 (R22)) to determine the trace levels of Pb(II) in solution. The limits of detection value were 6.67 nM, 8.61 nM, and 10.6 nM for R3, R10, and R22, respectively and were fully satisfied according to the guideline value of the World Health Organization for Pb(II) in drinking water. In addition, more than 90% of the initial activity for the reduction peak current remained up to 8 times for R3, 7 times for R10, and 5 times for R22. These results demonstrated that the geometric area ratio of the working electrode with the integrated silver counter to the quasi-reference electrode was significant to suggest that the geometric area ratio is an influencing factor in the electrochemical sensor performance.