Integrated Electrochemical Sensors

Ion Sensitive Field Effect Transistor (ISFET) for pH measurements

Ta2O5 insulating gate Ion Sensitive Field Effect Transistor (ISFET) devices measure the pH value in a wide range from basic to acidic solutions. The ISFET devices are realized with microelectronic technology compatible with CMOS processes allowing a wafer based sensor production.

Sensing Principle
The sensitive element is a Field Effect Transistor (FET), whose metal gate is replaced by a Reference Electrode and the solution of interest.
The sensing mechanism is based on the capacitive measurement of charged species on an insulating surface, such as Ta2O5.


Amperometric sensor for HOCl measurements

The integrated amperometric chlorine sensor is realized on silicon using microelectronic compatible processes. The thin film platinum working and counter electrodes as well as the silver/silver chloride reference-electrode are deposited on an electrically insulating silicon nitride layer.

Sensing Principle
The device is a miniaturized electrochemical cell consisting of a working-electrode (WE), a counter-electrode (CE) and a reference-electrode (RE). The HOCl concentration measurement is based on the electrical current generated by the reduction of HOCl at the working electrode at a fixed polarization voltage Vcell.


Applications
  • Environment control
  • Water quality
  • Chemical process control
  • Food quality control
  • Laboratories
  • Medical
Product Families:
  • Packaged single pH-ISFET sensor: MSFET 3330 (see Product page)
  • Interface electronics for the MSFET3330 sensors (see Product page)
  • Packaged single amperometric HOCl sensor: MAES (see Product page)
  • Miniature reference electrodes to work with the MSFET3330 and MAES sensors: MSREF (see Product page)


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