Detection of heavy metals using fully printed three electrode electrochemical sensor

A flexible three electrode electrochemical sensor was successfully screen printed on a polyethylene terephthalate (PET) film. Silver (Ag) ink, silver/silver chloride (Ag/AgCl) ink and carbon ink was used for the counter, reference and working electrodes, respectively. The feasibility of the fully printed sensor for detecting very low concentrations of toxic heavy metal ions was demonstrated. The electrochemical impedance spectroscopy (EIS) response of the printed sensor revealed a very high sensitivity at nano molar (nM) concentration levels of lead nitrate (Pb(NO
3
)
2
) and cadmium nitrate (Cd(NO
3
)
2
). A percentage change of 18 %, in impedance, was observed for the 1 nM concentration of Pb(NO
3
)
2
when compared with DI water. The response of the electrochemical sensor is analyzed and presented in this paper.