Development of a flow system for decentralized electrochemical analysis of heavy metals using screen-printed electrodes: the importance of sensor stability

Year after year, the need for decentralized tools to tackle the monitoring of heavy metal levels in the
environment gradually increases. In this context, suitable electrochemical methodologies are widely
established and particularly attractive for the production of low-cost miniaturized field-deployable analyti
cal platforms. This work focused on the development of an automatable portable system based on
square-wave anodic stripping voltammetry (SWASV) for the on-line detection of heavy metals. The
surface of the sensors is appropriately modified and coupled with a fluidic system equipped with an ad
hoc designed flow cell. A custom software tool was introduced to handle the remote-controlled poten
tiostat and automate the various steps of the procedure, including stirring operations, cleaning phases,
SWASV measurements, and data collection. After studying technical and analytical challenges, the final
system developed was applied to the simultaneous detection of Cd(II), Pb(II), and Cu(II) in solution, achiev
ing sub-ppb detection limits. Additionally, the practical applicability of the method was successfully
applied to river water samples collected from the Loire basin in France