CMOS compatible silicon nanowires (SiNWs) operated as ion-sensitive field-effect transistors (ISFETs) are investigated for the use as chemical and biochemical sensors. ISFETs are sensing devices based on metal oxide semiconductor field-effect transistors. Thereby the gate metal is replaced by the solution carrying the analyte species. The electrical potential of the solution affects the output of the ISFET. Reactions of charged analytes with corresponding ligand groups at the sensor surface cause a surface charge which leads to an additional surface potential. This change in surface potential is monitored and can be related to the number of adsorbed analytes.

Using different surfaces and surface functionalizations the sensitivity to specific target analytes can be tuned. We achieved ideal pH sensitivity and specific alkaline ion detection using arrays of silicon nanowires in a differential setup.

• Investigation of the dominant 1/f Noise Source in Silicon Nanowire Sensors 
  K. Bedner, V. A. Guzenko, A. Tarasov, M. Wipf, R. Stoop, S. Rigante, J. Brunner, W. Fu, C. David, M. Calame, J. Gobrecht, and C. Schoenenberger. 
  Sensors and Actuators B, 191, 270-275, 2014. 
• pH- Response of Silicon Nanowire Sensors: Impact of Nanowire Width and Gate Oxide 
  K. Bedner, V. A. Guzenko, A. Tarasov, M. Wipf, R. L. Stoop, D. Just, S. Rigante, W. Fu, R. A. and Minamisawa, C. David, M. Calame, J. Gobrecht, and C. Schoenenberger. 
  Sensors and Materials, 25 (8), 567-576, 2013. 
• Selective Sodium Sensing with Gold-Coated Silicon Nanowire Field-Effect Transistors in a Differential Setup 
  Mathias Wipf, Ralph L. Stoop, Alexey Tarasov, Kristine Bedner, Wangyang Fu, Iain A. Wright, Colin J. Martin, Edwin C. Constable, Michel Calame, and Christian Schoenenberger. 
  ACS Nano, 7 (7), 5978-5983, 2013. 
• Understanding the Electrolyte Background for Biochemical Sensing with Ion-Sensitive Field-Effect Transistors 
  A. Tarasov, M. Wipf, K. Bedner, J. Kurtz, Wangyang Fu, Vitaliy A. Guzenko, Oren Knopfmacher, Ralph L. Stoop, Michel Calame, and Christian Schoenenberger. 
  ACS Nano, 6 (10), 9291-9298, 2012. 
• A True Reference Nanosensor Realized with Silicon Nanowires 
  A. Tarasov, M. Wipf, K. Bedner, J. Kurtz, Wangyang Fu, Vitaliy A. Guzenko, Oren Knopfmacher, Ralph L. Stoop, Michel Calame, and Christian Schoenenberger. 
  Langmuir, 28 (25), 9899-9905, 2012.  
  [Abstract]
• Silicon-based ISFET shows negligible dependence on salt concentration at constant pH 
  Oren Knopfmacher, Alexey Tarasov, Mathias Wipf, Wangyang Fu, Michel Calame, and Christian Schoenenberger. 
  ChemPhysChem, 13 (5), 1157-1160, 2012.  
  [Abstract]
• Signal-to-noise ratio in dual-gated silicon nanoribbon field-effect sensors 
  A. Tarasov, W. Fu, O. Knopfmacher, J. Brunner, M. Calame, and C. Schoenenberger. 
  Appl. Phys. Lett., 98, 12114, 2011.  
  [Abstract]
• Nernst Limit in Dual-Gated Si-Nanowire FET Sensors 
  O. Knopfmacher, A. Tarasov, W. Fu, M. Wipf, B. Niesen, M. Calame, and C. Schönenberger. 
  Nano Letters, 10, 2268-2274, 2010. 
• Dual Gated Silicon Nanowire Field Effect Transistors 
  O. Knopfmacher, D. Keller, M. Calame, and C. Schönenberger. 
  Procedia Chemistry, 1(1), 678-681, 2009.