Electrochemical stripping determination of trace heavy metals using screen-printed electrodes as a versatile approach toward a mobile sensing platform

Access to reliable, portable, affordable, and versatile analytical platforms, for real-time and on-site water quality monitoring is key to safeguarding vulnerable species and the environment. In this context, we aimed to develop and implement an electrochemical methodology for the rapid (ca. 7 min) and effective simultaneous electrochemical detection of heavy metal ions of concern, i.e. cadmium, lead, and mercury in water sources, using a single screen-printed carbon electrode without any sophisticated modification. Four well- defined and fully resolved anodic stripping peaks, at −0.770, −0.540, −0.200, and 0.050 V (vs. Ag/AgCl) were observed for Cd, Pb, Cu, and Hg, respectively. After optimization of the effective parameters such as pH, type, and concentration of the supporting electrolyte along with instrumental parameters including conditioning potential, conditioning time, deposition potential, deposition time and frequency, square wave anodic stripping (SWASV) voltammetry was used to analyze Cd (II), Pb (II), Cu (II) and Hg (II) either alone or in their mixtures. The sensitivity of the proposed sensing platform was found to be 17.27 for Cd (II), 19.17 for Pb (II), and 10.96 for Hg (II) considering respective calibration curves. The convincing results are promising and envisage a solution to develop a cost-effective on-site monitoring platform for heavy metals at the trace level in seawater or drinking water.