BIOSENSING
Ultrasensitive detection of biomolecules with a label-free method has a significant value both in basic science and in clinical applications. Silicon nanochannel field-effect transistors have great promise for label-free biosensing. The sensitivity is enhanced at the nanoscale due to the large surface-to-volume ratio. Specificity is achieved by functionalizing the devices with selected antibodies or complimentary target molecules. These devices are important as building blocks for high density bio-nanoelectronics.
We show top-down fabricated silicon nanochannel devices with 3-dimensional relief can serve as a platform for biosensing applications. The top-down fabrication of these devices is compatible with advanced microfabrication processes, and enables scalable manufacturing. Three sides of the silicon nanowire are covered with a thin Al 2 O 3 layer using Atomic Layer Deposition to form an insulating layer. When the surface is modified for binding to specific biomarkers, the device conductance change can be used to detect binding events through a field effect.
We demonstrate various types of applications for the silicon nanochannel biosensors. Developed from the silicon nanochannel platform, our devices are shown to be used as immunosensors by detecting biotin-antibiotin interaction. We also construct enzyme-based sensors using our devices to detect metabolites like glucose and urea.