Multi-Ion Potential Sensor and Fabrication thereof

A multi-ion potential sensor fabrication method, comprising the steps of:

• providing a substrate;
• forming a conductive layer on said substrate by using screen-printed method, wherein said conductive layer comprises a plurality of independent conductive areas, and each of said conductive areas comprises a readout area, a transmissive area and a sensing area, wherein said readout area is connected with one side of said transmissive area, and said sensing area is connected with the other side of said transmissive area;
• deposting a tin oxide layer on said conductive layer by vapor deposition method, wherein said tin oxide layer comprises a plurality of independent tin oxide areas, and each of said tin oxide areas is respectively deposited on each of said sensing areas;
• forming an isolation layer over each of said transmissive areas;
• forming a selective layer on said tin oxide layer, wherein said selective layer comprises a plurality of independent selective areas, and each of said selective areas is set on each of said tin oxide areas.

A solid-state reference electrode fabrication method, comprising the steps of:

• providing a silver layer which is connected with a wire;
• electrifying said silver layer to form a silver oxide (AgCl) layer around said silver layer;
• forming an ion containing polymer around said silver oxide layer;
• and
• forming an insulation layer around the place of connection between said silver layer and said wire.