The objective of this research is to develop fundamental understanding on how the performance of nanoscale field effect transistor biosensors depends on device geometrical sizes at different physical conditions. The approach is to numerically investigate device scaling behaviors at various physical conditions by using a random resistor network model and experimentally test these scaling laws at different field effect strengths by using Si-based devices as a model system. Intellectual Merit: The outcome of this research will answer the fundamentally intriguing and technologically important question on whether and how the sensitivity and detection limits of field effect biosensors depend on their geometrical dimensions and relevant physical parameters. The project is transformative in terms that scaling laws for field effect biosensors as critical design guidelines will enable tailoring the sensitivity and detection limits in accordance with target analyte concentrations, and enable design of devices with ultra-low detection limits. Broader Impacts: Ultra-sensitive biosensors can find various applications from food safety, homeland security to disease diagnostics for human health care. Graduate and undergraduate students will be trained in this interdisciplinary project on device and computational physics, semiconductor nanostructure fabrication and characterization, and surface and interface biochemistry. Special efforts will be made to recruit female and underrepresented minority students for participation. Research discoveries from this project will be incorporated into the courses developed by the principle investigators. Outreach activities include school visits, training of high school senior students, and participation of NSF GK-12 Program.
