Ion sensor for fluid and method for its manufacture

A method for the measurement of a concentration of a charged species

• in a sample, the sample having a plurality of types of charged species and at least one insoluble component, the method comprising:
• providing the sample on a surface of a partly permeable layer, wherein the partly permeable layer comprises one or more openings in a layer covering a channel;
• allowing components of the sample to pass through the partly permeable layer into the channel;
• separating the components inside the channel into sections, such that each at least one of the sections substantially comprises a single type of the plurality of the types of charged species;
• and
• determining the species concentration in the sections.

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:

• at least one channel with at least one opening;
• a partly permeable layer covering the at least one opening, wherein the partly permeable layer comprises one or more openings in the channel;
• 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 substrate;
• providing a first cover layer;
• forming a channel into the substrate or into the first cover layer;
• placing said first cover layer on the substrate, such that the first cover layer and the substrate close the channel, whereby the first cover layer and the substrate together comprises at least one opening providing access to the channel;
• and
• placing a partly permeable layer on the at least one opening, wherein the permeable layer consists of one or more openings towards the channel.