Fabrication of a Pseudo-reference Electrode on a Flexible Substrate and Its Application to Heavy Metal Ion Detection

Flexible electrochemical sensors with three- electrode configuration are useful for various in-situ measurements of electroactive species. An electrochemical modification of a printed silver layer is presented as a method to integrate a mechanical and electrochemically stable pseudoreference electrode. The surface morphologies and compositions of the pseudo-reference electrode were characterized by a scanning electron microscope, an energy dispersive X-ray spectroscopy (EDS) analysis, and an X-ray photoelectron spectroscopy (XPS) analysis. The electrochemical performance of the integrated pseudo-reference electrode was studied using potassium ferricyanide as a probe molecule and compared against the results obtained from a commercial reference electrode. Its application towards heavy metal ion detection in aqueous solutions was demonstrated.