Iron nanoparticles and nanowires as modifiers of carbon paste electrodes for the detection of traces of copper, lead, and zinc ions in water

This work describes the application of nano-iron modified carbon paste electrodes (CPEs) for the detection of copper, lead, and zinc ions in aqueous solutions. The CPEs were manufactured by mixing commercial graphite powder with mineral oil and two types of iron nanomaterials, namely iron nanoparticles (Fe-NPs) and iron nanowires (Fe-NWs) whose preparation processes and properties were also presented herein. Preliminary electrochemical results showed that the CPEs modified with Fe-NWs (10% relative to the graphite) possessed a larger electrochemically active surface area in a comparison with unmodified electrodes and those modified with Fe-NPs. The current responses of investigated electrodes depended on the type of metal ion and its concentration. Contrary to previous literature reports on the modification of CPEs, higher current responses and lower detection limits were found for electrodes prepared with Fe-NWs. This indicates that the Fe-NWs constitute a promising modifier of CPEs for sensor application.