Electronic Detection of Functional Cellular Immunity Using Enzymatic Metallization.

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.