Fabrication of Si Nanowire Field-Effect Transistor for Highly Sensitive, Label-Free Biosensing

We fabricated a biosensor based on a silicon nanowire field-effect transistor (SiNW FET) with a Si3N4 gate insulator for highly sensitive detection of target biomolecules. The fabricated SiNW FET acted as an ion-sensitive FET that could detect the charge density in solutions flowing along the gate surface by responding to the pH of the solutions. The SiNW FET also detected charged protein molecules in solution, suggesting that our device can be used in highly sensitive, label-free biosensing.