Ion sensor based on differential measurement, and production method

A device comprising an ion sensor based on differential measurement, wherein the sensor comprises:

• (i) a substrate whereon are integrated connection tracks;
• (ii) an electrode of a conductor material arranged to be in contact with a solution to measure;
• (iii) a first ion-selective field effect transistor and a second ion-selective field effect transistor electrically connected by the connection tracks to an ion measurement system, each of the first and second ion-selective field effect transistors being fixed on the substrate and having a gate;
• (iv) a structure coupled only on the first ion-selective field transistor configured to create a microreservoir on the gate of the first ion-selective field effect transistors, wherein the gate of the first ion-selective field effect transistor is arranged to be in contact with a reference solution and the gate of the second ion-selective field effect transistor is arranged to be in contact with the solution to measure;
• and,
• (v) at least one microchannel connecting the microreservoir with the exterior of the ion sensor through an outlet orifice of the at least one microchannel, the at least one microchannel configured to calibrate the ion sensor by filling or renewing the microreservoir with the reference solution and comprising a first longitudinal section.

A device comprising an ion sensor based on differential measurement, wherein the ion sensor comprises;

• (i) a first ion-selective field effect transistor and a second ion-selective field effect transistor, electrically connected by connection tracks to an ion measurement system and each ion-selective field effect transistor having a gate;
• (ii) an electrode arranged to be in contact with a solution to measure;
• (iii) at least one chip on the surface whereof are integrated the ion-selective field effect transistors;
• (iv) a structure adhered on the first ion-selective field effect transistor configured to create a microreservoir on the gate of only the first ion-selective field effect transistor the microreservoir being filled with a reference solution, wherein the first ion-selective field effect transistor is arranged to be in contact with the reference solution and the second ion-selective field effect transistor is in contact with a solution to measure;
• (v) at least one microchannel having an outlet, the at least one microchannel connecting the microreservoir with the exterior of the structure, the at least one microchannel being filled with the reference solution;
• (vi) a substrate whereon is integrated the at least one chip, the connection tracks and the electrode;
• and,
• (vii) an encapsulating material which completely insulates the connection tracks and partially insulates the first and second ion-selective field effect transistors of the solution to measure, wherein the gates of the first and second ion-selective field effect transistors and the outlet of the microchannel are uncovered.