IEM Seminar Series: Digital sensing with CMOS-based nanocapacitor arrays: Formation of lipid-supported bilayers as case study


Event details

Date 07.12.2022 15:0016:00  
Speaker Serge G. Lemay
University of Twente, Faculty of Science and Technology & MESA+ Institute for Nanotechnology
Location Online
Category Conferences - Seminars
Event Language English
While representing the ultimate limit in mass sensitivity for a given analyte, single-entity electrochemical (bio)sensors typically have limited concentration sensitivity due to their small physical dimensions. One route to overcoming this hurdle is to employ large numbers of parallelized devices, each capable of single-entity detection.  An example of such an architecture is CMOS-based nanocapacitor arrays, which allow locally probing the impedance of an electrolyte in real time and with sub-micron spatial resolution. At sufficiently high frequencies the electric field penetrates beyond the electrical double layer caused by screening ions, allowing a form of electrochemical imaging of micron-sized synthetic and biological entities. For nanoscale analytes, on the other hand, the response takes the form of discrete, step-like changes in impedance upon binding to the surface of an electrode. Here we illustrate these capabilities by monitoring in real time the formation of a supported lipid bilayer from the fusion of lipid vesicles. Several nanoscale vesicles are detected as they impinge upon the surface of each individual electrode and gradually cover its surface. Even though the impedance signal at each of the 216 electrodes is stochastic in nature, the total response exhibits the smooth behavior expected for the formation of a macroscopic lipid bilayer. This work is a collaboration with NXP Semiconductors.

Serge G. Lemay received a B.A.Sc. in Electrical Engineering with minor in Physics from the University of Waterloo, Canada, in 1993, and a Ph.D. in Physics from Cornell University, USA, in 1999. He was faculty at Delft University of Technology, The Netherlands, from 2001 to 2009. In 2009 he relocated to the University of Twente, The Netherlands, where he heads the Bioelectronics group, part of the Faculty of Science and Technology and the MESA+ Institute for Nanotechnology. His research has spanned solid-state physics (charge-density waves), molecular electronics (quantum effects in carbon nanotubes) and biophysics (DNA electrostatics). His main interests at present include the fundamentals of electron transfer in liquid, in particular electrochemical nanofluidic devices, and exploring digital transduction mechanisms for biosensing.