Development and test of a planar reference electrode for multipanel electrolyte sensor

**** Master Project ****


Contacts: Dr. MER Sandro Carrara, Senior Scientist, EPFL-IC-ISIM-LSI                
                  Ms. Irene Taurino, Post-doctoral researcher, EPFL-IC-ISIM-LSI



The most frequent blood alterations of patients in intensive care units (ICUs) regard electrolytes. Some of these ions rapidly change causing significant health problems. Therefore, a continuous monitoring of target ions in critical patients is an urgent need.

Potentiometric ion sensors are the only class of devices that can control in real time the concentration level of ions. Ideally, these sensors should be put in contact with the patient blood by inserting them in cannula/catheters connected to the patient. Therefore, their miniaturization is an important requirement and durable miniature reference electrode (RE) fully integrated with the platform is necessary.

A stable RE is particularly important for potentiometric readings because RE is responsible for half of the signals. Its stability ensures the sensor to work effectively. Commonly used REs contain an inner-filling solution that causes numerous disadvantages such as the need of maintenance, the high cost of manufacture, the contamination of the sample due to problems of leakage, their use only in a vertical position to keep the contact sample/liquid junction, the difficulty of miniaturization. Goal of the project is the realization and test of a solid-contact RE (with no inner-filling solution) fully integrated onto a multipanel potentiometric sensor to simultaneously detect different ions of medical interest.


  • Build different RE and test their sensitivity to interferences, light, temperature, ions, pH, stirring of the solution.
  • Selection of the best RE for sensing ions of medical significance (K+, Na+) and pH and comparative study with a commercial double junction RE Ag|AgCl.
  • Simultaneous sensing of two ions with a multisite potentiometric device and the integrated RE in synthetic buffer solution.
  • Simultaneous sensing of two ions with a multisite potentiometric device and the integrated RE in serum within the relative physio-pathological concentration ranges in real sample
  • Multisensing measurements by using a read-out circuit on a PCB board which includes also a Bluetooth® module to send the measured data to a mobile device and display them on the screen thanks to an Android interface.

Eligibility Requirements:

  • Basic knowledge on electrochemical sensors

  • Basic knowledge of materials and chemistry
  • Interest and motivation