Ion Sensitive Field-Effect Transistor (ISFET)


The Ion Sensitive Field Effect Transistor (ISFET) is a solid state, potentiometric sensor capable of measuring pH in the range of pH 1 to pH 14 with a linear response.


Various customers need customized ISFETs with high sensitivity, low drift, and low light sensitivity; especially now, as replacements are required for the discontinued Honeywell ISFET sensor.


We developed a solution based on ion implantation, gate oxidation, diffusion, and a tantalumoxide (Ta2O5) gate material. The device is customizable and uncalibrated, allowing for full access to the sensor.

More information on this poster, which was published on the 3rd Conference on MicroFluidic Handling Systems, 4-6 October 2017, Enschede, the Netherlands.

ISFET Evaluation

Do you need to evaluate an ISFET pH sensor without commitment? LioniX International has teamed up with Microsens SA to offer a cost-effective measurement kit with with an ISFET sensor, electronics and interfacing for evaluation. The kit includes:

  • A packaged ISFET sensing element
  • A USB interface
  • A reference electrode
packaged isfet for evaluation