pH sensing from frequency response of SGFET

This paper presents suspended gate field effect transistors (SGFET) used as highly sensitive pH sensors. The devices are there characterized in dynamic mode. The gain, measured versus frequency, is studied for different pH values and shows a resonance frequency depending on the pH value. These results, obtained with different geometries of SGFET, give an opportunity to develop new microsystems, CMOS compatible, highly sensitive to pH.