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

Description:
CMOS-based nanocapacitor arrays 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 [1,2]. 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 [3]. Here we illustrate these capabilities by monitoring in real time the formation of a supported lipid bilayer from the fusion of lipid vesicles [4]. For each individual electrode, several nanoscale vesicles are detected as they impinge upon and gradually coat its surface. Even though the impedance signal at each of the ~65,000 electrodes is stochastic in nature, the aggregate response exhibits the smooth behavior expected for the formation of a macroscopic lipid bilayer. This work is a collaboration with NXP Semiconductors.

1. C. Laborde, F. Pittino, H. A. Verhoeven, S. G. Lemay, L. Selmi, M. A. Jongsma, F. Widdershoven, Real-time imaging of microparticles and living cells with CMOS nanocapacitor arrays. Nat. Nanotechnol. 2019, 10, 791–795.
2. C. Renault, C. Laborde, A. Cossettini, L. Selmi, F. Widdershoven, S. G. Lemay, Electrochemical characterization of individual oil micro-droplets by high frequency nanocapacitor array imaging. Farad. Disc. 2022, 233, 175 – 189.
3. F. Widdershoven, A. Cossettini, P. P. van Swinderen, S. G. Lemay, L. Selmi, A CMOS pixelated nanocapacitor biosensor platform for high-frequency impedance spectroscopy and imaging. IEEE Trans. Biomed. Circ. Syst. 2018, 12, 1369–1382.
4. D. di Iorio, M. L. Verheijden, E. van der Vries, P. Jonkheijm, J. Huskens, Weak multivalent binding of influenza hemagglutinin nanoparticles at a sialoglycan-functionalized supported lipid bilayer. ACS Nano 2019, 13, 3413–3423.

Speaker: Serge Lemay - University of Twente
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. His research has spanned solid-state physics, molecular electronics and biophysics. His main interests at present include single-entity electrochemistry and AC signal transduction in biosensors.