3D-Printed electrochemical sensor-integrated transwell systems

Pradeep Ramiah Rajasekaran; Ashley Augustiny Chapin; David N Quan; Jens Herberholz; William E Bentley; Reza Ghodssi

doi:10.1038/s41378-020-00208-z

3D-Printed electrochemical sensor-integrated transwell systems

Microsyst Nanoeng. 2020 Oct 5:6:100. doi: 10.1038/s41378-020-00208-z. eCollection 2020.

Authors

Pradeep Ramiah Rajasekaran¹, Ashley Augustiny Chapin^{1

2}, David N Quan², Jens Herberholz³, William E Bentley^{2

4

5}, Reza Ghodssi^{1

2

5

6}

Affiliations

¹ Institute for Systems Research, University of Maryland, College Park, MD USA.
² Fischell Department of Bioengineering, University of Maryland, College Park, MD USA.
³ Department of Psychology and Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD USA.
⁴ Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD USA.
⁵ Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD USA.
⁶ Department of Electrical and Computer Engineering, University of Maryland, College Park, MD USA.

Abstract

This work presents a 3D-printed, modular, electrochemical sensor-integrated transwell system for monitoring cellular and molecular events in situ without sample extraction or microfluidics-assisted downstream omics. Simple additive manufacturing techniques such as 3D printing, shadow masking, and molding are used to fabricate this modular system, which is autoclavable, biocompatible, and designed to operate following standard operating protocols (SOPs) of cellular biology. Integral to the platform is a flexible porous membrane, which is used as a cell culture substrate similarly to a commercial transwell insert. Multimodal electrochemical sensors fabricated on the membrane allow direct access to cells and their products. A pair of gold electrodes on the top side of the membrane measures impedance over the course of cell attachment and growth, characterized by an exponential decrease (~160% at 10 Hz) due to an increase in the double layer capacitance from secreted extracellular matrix (ECM) proteins. Cyclic voltammetry (CV) sensor electrodes, fabricated on the bottom side of the membrane, enable sensing of molecular release at the site of cell culture without the need for downstream fluidics. Real-time detection of ferrocene dimethanol injection across the membrane showed a three order-of-magnitude higher signal at the membrane than in the bulk media after reaching equilibrium. This modular sensor-integrated transwell system allows unprecedented direct, real-time, and noninvasive access to physical and biochemical information, which cannot be obtained in a conventional transwell system.

Keywords: Chemistry; Electrical and electronic engineering.

Grants and funding

R21 EB024102/EB/NIBIB NIH HHS/United States