A readily disposable ion selective electrode assembly, free of onboard reagents, for use in analyzers has a reference element and plural sensor elements linearly positioned in parallel on a substrate. An elastomeric flow channel member containing two parallel grooves creates flow channels on the substrate above the elements. The substrate holds the elastomer in compression and is retained by snaps injection molded into a housing. Electrical contacts and leakfree fluidic connections are provided by spring loaded connectors through the housing. Reference and sample fluids are drawn through the respective flow channels and come together to form a liquid junction downstream from the sensor elements. Bubbles, that might otherwise cause erroneous results, are detected.