Planer-type liquid junction Ag/AgCl reference electrode and its application in a potentiometric biosensor

A planer-type liquid junction Ag/AgCl reference electrode was developed using screen-print technology. The experimental results indicate that the potential shift of the planer-type liquid junction reference electrode was between 5 to 15 mV when the chloride ion concentration was in the range 10^-6 to 0.3 M at a potential of 2 mV at pH=2 to 10. Restated, the potential shift is 1.5 to 2 mV as the chloride ion concentration changes by one order of magnitude and the pH of the solution has no effect. The pH measured using a planer-type liquid junction did not differ significantly from that obtained using a commercial reference electrode.