Laser-pyrolysed paper electrodes for the square-wave anodic stripping voltammetric detection of lead

Abstract

Single-use screen-printed electrodes are relatively economical, still, they may not be cheap enough for low-income countries when including shipping costs, places where often in situ water analysis is of great relevance. This work displays the proof of concept of applying laser-pyrolysed paper electrodes (LPPEs) for lead (Pb) quantification. By simply and carefully burning ordinary cardboard with a commercially available CO₂ laser, it was possible to fabricate low-cost electrodes with a carbon-based material as the electroactive surface. By means of square-wave anodic stripping voltammetry (SWASV), and using zinc (Zn) as an internal standard (E_p = −1.02 vs. Ag), a limit of detection (LOD) of 6 ppb was attained for lead (E_p = −0.46 V vs. Ag) along with other suitable analytical performance parameters, such as 4% of repeatability and 5% of reproducibility.