Understanding and Beating the Sensitivity Limit of
Nanowire Field-Effect Transistor Biosensors
Chi On Chui
Assistant Professor of Electrical Engineering
Member of California NanoSystems Institute
University of California, Los Angeles, CA 90095, USA
After over 10 years of development, semiconductor nanowire field-effect transistor (FET) sensors have substantially advanced and shown great promises in label-free and real-time electronic detection of important disease biomarkers with high sensitivity and specificity. From an electrical engineer’s perspective, the intrinsic detection sensitivity limit would need to be explored, and extended if at all possible, before judging their field deployment readiness.
In this talk, I will first reveal a theoretical framework that correlates for the first time the nanowire FET biosensor response to the type of target analytes, counter-ion strength, and biasing regime. Using this framework, we are able to explain practically all experimental data on immunodetections and solution pH detections with silicon nanowire (and even carbon nanotube) FET biosensors. Moreover, I will discuss the length dependent sensitivity of nanowire FET sensors and our hypothesized physical explanation. In the last part, I will disclose a novel nanowire-based FET sensing device concept by seamlessly integrating a nanowire FET sensor with a nanowire amplifier. On the pre-optimized novel sensing devices, we have experimentally demonstrated an at least one order of magnitude improvement in pH and immunodetection detection sensitivity over the generic nanowire FET sensors.
Chi On Chui received the B.Eng. degree in Electronic Engineering (with highest honors) from Hong Kong University of Science and Technology (HKUST) in 1999, and the M.S. and Ph.D. degrees in Electrical Engineering from Stanford University in 2001 and 2004, respectively. He joined Intel Corporation as a Senior Device Engineer in 2004 and also served as a Researcher-in-Residence at the University of California, Berkeley and at Stanford University. From 2005-2006, he was also appointed Consulting Assistant Professor of Electrical Engineering at Stanford University. He joined the University of California, Los Angeles (UCLA) in 2007 as an Assistant Professor of Electrical Engineering and becomes a Member of the California NanoSystems Institute (CNSI) since 2009.
Professor Chui has been a nanoelectronic semiconductor device and nanofabrication technologist throughout his professional career in both academia and industry with over 11 years of extensive experience in designing, processing, and characterizing all major semiconductor devices made out of silicon, germanium, III-V compounds, and graphitic materials. At UCLA, his laboratory has active research projects to develop unconventional nanostructure devices and technology for architectonics, theranostics, and ultrahigh speed electronics. He has authored and co-authored more than 95 peer-reviewed and invited archival journal and conference papers, and 5 book chapters. He also has 7 issued and few pending patents in semiconductor device technology. Besides, he has received several awards for his work including 3 best paper awards. Most notably, he is the 1st recipient of the IEEE Electron Device Society Early Career Award in 2009, which is regarded as one of the Society’s highest honors. He also received the Chinese American Faculty Association Robert T. Poe Faculty Development Award. Very recently, he has been selected to receive the school-wise Northrop Grumman Excellence in Teaching Award.