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Fabrication of a Solution-gated Indium-Tin-Oxide-based One-piece Transistor Enabling Sensitive Biosensing
Published on: August 29, 2025
Understanding the electrolyte background for biochemical sensing with ion-sensitive field-effect transistors
Alexey Tarasov1, Mathias Wipf, Ralph L Stoop
1Department of Physics, University of Basel, Basel, Switzerland. alexey.tarasov@unibas.ch
ACS Nano
|September 29, 2012
Summary
Silicon nanowire sensors show a nonlinear response to electrolyte concentration changes, driven by anion adsorption. A new model accurately describes this behavior, advancing biosensing technology.
Area of Science:
- Materials Science
- Nanotechnology
- Biochemistry
Background:
- Silicon nanowire field-effect transistors (FETs) are promising for biochemical sensing.
- Their response to electrolyte concentration variations requires further clarification.
Purpose of the Study:
- To investigate the response of HfO(2) and Al(2)O(3) coated silicon nanowires to KCl concentration changes at constant pH.
- To develop a model explaining the observed sensor response.
Main Methods:
- Fabrication of silicon nanowires coated with hafnium oxide (HfO(2)) and aluminum oxide (Al(2)O(3)).
- Measurement of sensor response under varying KCl concentrations and constant pH.
- Comparison of experimental data with existing theoretical models.
Main Results:
- A nonlinear sensor response to ionic strength was observed, independent of pH.
- The response is attributed to the adsorption of chloride anions (Cl(-)) rather than potassium cations (K(+)).
- Existing models failed to explain the experimental data.
Conclusions:
- A novel model was developed that accurately quantifies the sensor response to electrolyte concentration.
- This work clarifies the sensing mechanism of oxide-coated silicon nanowires in electrolyte solutions.
- The findings contribute to the development of more reliable silicon nanowire-based biosensors.
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