Microelectronic sensors for simultaneous measurement of PO2 and pH

Sensors capable of simultaneous measurement of pH and PO2 in an aqueous solution have been fabricated in planar form using microelectronic technology. Separate potentiometric metal-metal oxide pH and three electrode amperemetric PO2 sensors have been fabricated together on a silicon chip with active surface of 2 x 3 mm. Rhodium-rhodium oxide electrodes operating in a cyclic voltammetry mode have also been studied and show sensitivity to both pH and PO2 in different regions of the voltage swept curve.