Study of field effect transistors for the sodium ion detection using fluoropolysiloxane-based sensitive layers

Arnaud Cazalé (1, 2) , William Sant (1) , Jérôme Launay (2) , Frédéric Ginot (1) , Pierre Temple-Boyer (2)

1 HEMODIA SA
2 LAAS-MICA - Équipe MICrosystèmes d'Analyse

A membrane for the development of Na + sodium ion sensitive field effect transistor (pNa-ISFET) is described in this work. This membrane is based on a fluoropolysiloxane (FPSX) polymer modified by sodium ionophore. The advantages of using such polymer are several: it permits good adhesion properties on silicon-based layers, it is characterized by a lower resistivity and it is fully compatible with ink jet printing technique. Thus, FPSX membranes were developed in the frame of a pH-ChemFET / Ag/AgCl reference electrode industrial fabrication process. Studies involve the deposition of FPSX-based, sodium ion sensitive layers by ink jet printing, the integration and characterization of Ag/AgCl reference electrode, as well as the pNa measurement in solution. Thus, whatever the reference electrode used, FPSX-based pNa-ISFET microsensors show good detection properties with sensitivity around 57 mV/pNa, detection limit around 10-4 M, low pH interferences (7 mV/pH in the [9-12] basic range) and selectivity coefficient versus potassium K + ion-3. Final application is done through analysis of real sweat samples.

Mots clés: ion-sensitive layers; sodium ion detection 2; ISFET sensor; inkjet printing

Domaines: Micro et nanotechnologies/Microélectronique; Chimie analytique

Arnaud Cazalé, William Sant, Jérôme Launay, Frédéric Ginot, Pierre Temple-Boyer. Study of field effect transistors for the sodium ion detection using fluoropolysiloxane-based sensitive layers. Sensors and Actuators B: Chemical, 2013, 177, pp.515-521. ⟨10.1016/j.snb.2012.11.054⟩. ⟨hal-01508086⟩