# Three-dimensional field effect transistor arrays as a platform technology for intracellular electrophysiology recording.

> **NIH NIH R35** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2024 · $200,000

## Abstract

Project Summary of the Parent Award
Most cellular behaviors and functions rely on cell signaling. A direct approach to detect this event is to
record cellular electrical potentials that are associated with various ionic kinetics during signal processing. It
has been shown that a wide range of high profile diseases, such as epilepsy, episodic ataxia,
Alzheimer's, and Parkinson's, may result from dysfunction of voltage-gated sodium, potassium, and calcium
channels. Although qualitative knowledge of the motions of these ions has been well studied, a quantitative
understanding is still missing because of the lack of tools that would allow high-spatiotemporal-resolution
sampling of ion motions inside cells. My group is dedicated to developing a soft electronic interface for cells
and tissues. This synthetic electronic interface will have similar mechanical properties to the biology, and
can organically fuse with the target cells and tissues, which will not only result in higher signal to noise ratio
but also longer recording time than conventional rigid and bulky recording systems. This five-year project
aims to develop an innovative cellular interface that is composed of an array of highly sensitive three-
dimensional field effect transistor (FET)-based sensors on a stretchable substrate. We use this innovative
cellular interface to test the hypothesis that ionic kinetics, including the speeds of ionic diffusion through ion
channels in the cell membrane, ion drift driven by ion pumps, and inter-cellular signal propagation, entail
crucial quantitative information associated with disorders of electrogenic cells, such as neurons,
cardiomyocytes, and electrically excitable endocrine cells. The sensors can simultaneously record different
positions of a single cell or among different cells in a cellular network, thus enabling us to measure and
calculate the time- or speed-related kinetic factors of the ions (i.e., the time at which the ions move in or out of
the cell membrane and the speed at which they do, respectively). Also, using an FET design, we can amplify
the recorded signal directly at the targeting location, realizing as much as ten-fold signal amplification.
Furthermore, we can differentiate the specific ionic species that are actively functioning inside and outside
of the cells by coating the surfaces of the FET sensors with phospholipid bilayers that have the corresponding
ion channels, allowing the specific ions to permeate the cell membrane, which would result in a change in
electrical potential that could be recorded by the FET sensors. The information acquired will help gain
new insights in cellular communications, with profound implications for brain sciences, cardiac physiology, and
clinical practices.

## Key facts

- **NIH application ID:** 11071717
- **Project number:** 3R35GM138250-05S1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Sheng Xu
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $200,000
- **Award type:** 3
- **Project period:** 2020-09-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11071717

## Citation

> US National Institutes of Health, RePORTER application 11071717, Three-dimensional field effect transistor arrays as a platform technology for intracellular electrophysiology recording. (3R35GM138250-05S1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/11071717. Licensed CC0.

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