Development of a planar type ion sensor for urine testing

A new planar-type ion sensor with an Ag/AgCl electrode without a standard solution and liquid junction was proposed for urine testing. The proposed sensor integrates a reference electrode onto a single chip, and thus, it is possible to manufacture a compact planar-type ion sensor. The potential change of the developed sensor is proportional to the Na⁺ and K⁺ concentration. Although the Ag/AgCl electrode without a standard solution and liquid junction reacted to Cl^-, AC impedance analysis was used to compensate the effect of Cl-on the potential change. Therefore, the proposed planar-type ion sensor can be used for routine urine testing because the proposed sensor is low cost, disposable, and also has a simple structure.