# Digital Detection of DNA via Impedimetric Tracking of Probe Nanoparticles

## TL;DR

A new method uses nanocapacitor arrays to detect DNA by tracking nanoparticle movements, offering a scalable and precise biosensing approach.

## Contribution

The study introduces a specific DNA detection method using nanoparticle displacement and nanocapacitor arrays, capturing complex spatiotemporal signals.

## Key findings

- Strand displacement assays link DNA hybridization to nanoparticle displacement, generating detectable electrical signatures.
- The system captures localized interactions with high resolution, surpassing conventional impedance spectroscopy.
- The architecture supports scalable and cost-effective biosensing for clinical diagnostics.

## Abstract

CMOS-based nanocapacitor arrays are an emerging technology
that
permits spatially resolved, high-frequency impedance measurements
at the nanoscale. Their capability to detect micro- and nanoscale
entities has already been established through nonspecific interactions
with the targets. Here, we demonstrate their application in specific
macromolecular capture and detection using single-stranded DNA (ssDNA)
as a model analyte. While individual ssDNA strands fall below the
detection threshold, we employ a strand displacement assay that links
DNA hybridization to target ssDNA induced displacement of reporter
nanoparticles. This displacement reaction results in distinct electrical
signatures with complex spatiotemporal patterns, details that remain
unresolved in conventional macroscale impedance spectroscopy techniques
due to their limited resolution and signal averaging that obscures
localized interactions. The proposed system’s massively parallel
architecture and the ability to detect complex dynamics of individual
nanoparticle–nanoelectrode interactions make it a promising
candidate for scalable, portable, and cost-effective biosensing applications
in clinical diagnostics and beyond.