# Electronic Detection of Functional Cellular Immunity Using Enzymatic Metallization

## TL;DR

A new electronic method called EPIC detects immune cell function without the need for fluorescent labels, offering a low-cost and scalable alternative for diagnostics.

## Contribution

EPIC combines enzymatic metallization and impedance analysis for electronic immune profiling at the single-cell level.

## Key findings

- EPIC generated distinct impedance signatures in Jurkat cells and human blood cells based on surface metallization.
- Impedance readouts from EPIC matched flow cytometry results for detecting IFN-γ secretion.
- The EPIC system shows potential as a low-cost, scalable alternative to fluorescence-based assays for immune diagnostics.

## Abstract

Accurate detection
of immune cell function at the single-cell level
is needed for diagnostic and research applications, yet conventional
methods such as flow cytometry require complex instrumentation and
fluorescent labeling which limits their use in resource-poor settings.
To address this limitation, we developed Electronic Phenotyping using
Impedance Cytometry (EPIC), a platform that combines antibody-directed
enzymatic metallization on the cell surface with multifrequency impedance
analysis, in a microscale 3D-printed plastic aperture, to electronically
detect surface marker-based metallization and cytokine secretion.
Using CD45-targeted metallization, EPIC generated distinct impedance
signatures in Jurkat cells and primary human peripheral blood mononuclear
cells, with impedance changes correlating to surface metallization.
A bispecific capture strategy coupled to the metallization was then
used for detection of IFN-γ secretion of cells, with impedance
readouts matching flow cytometry. These findings demonstrate the ability
of the EPIC system for sensitive electronic immune profiling and support
its potential as a scalable, low-cost alternative to fluorescence-based
assays for point-of-care cellular immunity based diagnostics.