[18a-E202-1~11] 12.7 Biomedical Engineering and Biochips

▲ [18a-E202-1] Evaluation of sodium ion responsivity with InAs nanowire field-effect transistors functionalized by ionophore-doped fluorosilicone membranes

〇(D)Alex ChiWei Tseng¹, Harry E. Ruda², Toshiya Sakata¹ (1.The Univ. of Tokyo, 2.Univ. of Toronto)

Keywords:ion sensor, nanowire field-effect transistor, ion-sensitive membrane

Field-effect transistors (FETs) based on semiconducting nanowire (NW) materials are promising for electronic chemical and biological sensors due to the ability to detect and amplify small signals originating from the charge of target molecules. In particular, nanoscaled dimensions suggest the potential for high sensitivity due to surface effects on electronic transport and similar length scales between device, target size, and charge screening length. In this study, NW-FETs are prepared from InAs NWs and subsequently functionalized by depositing ionophore-doped fluorosilicone membranes. This gives selectivity for sodium ions by the chemical equilibria of complexation. Responsivity towards ion activity is evaluated by changes in surface potential as determined by the threshold voltage extracted from FET transfer characteristics. Hysteresis observed in these measurements suggest the possibility of tuning the apparent ion sensitvity by controlling the electrostatic history of the device.