Ion sensor for fluid and method for its manufacture

An apparatus for the measurement of a concentration of a charged species in a sample, the sample comprising a plurality of types of charged species and at least one insoluble component, the apparatus comprising:

• a non-conducting substrate;
• at least one channel formed in the non-conducting substrate and with
• one or multiple openings at the location of the sample contact area and wherein the at least one channel is otherwise closed;
• a first layer covering the at least one opening, wherein the first layer comprises one or more holes in the first layer covering the at least one channel, and wherein the at least one channel is otherwise sealed;
• a removable protection cober cobering at least pertly a surface of the first layer and the at least one opening;
• at least two electrodes arranged along the at least one channel on each side of the opening;
• and at least one sensor for measuring at least one type of charged species in the at least one channel.

A method for the production of an apparatus comprising:

• providing a non-conducting substrate;
• providing a first layer and a protection cover;
• forming a channel into the substrate or into the first layer;
• placing said first layer on the non-conducting substrate, such that the first layer and the substrate close the channel, whereby the first layer and the substrate together comprise at least one opening providing access to the channel, wherein the first layer comprises one or more holes towards the channel, wherein the channel extends to at least one side of the at least one opening;
• placing the protection cover over the fist layer, such that the protection cover substantially seals the channel.