# A Bipolar Electrochemical Single Entity Bioanalyzer

> **NIH NIH R21** · UNIVERSITY OF WASHINGTON · 2024 · $217,922

## Abstract

Abstract
This proposal is in response to NIH FOA (PAR-22-126), which “supports exploratory research leading to the
development of innovative technologies for biomedical research...” This R21 project aims to harness the high
sensitivity and resolving power of optical microscopy and asymmetric bipolar microelectrode arrays to develop
a low-cost, highly sensitive bipolar electrochemical array platform for detecting and counting individual
biological target species.
 Many biologically or clinically relevant species, such as certain cancer biomarkers, present at very low
concentrations, sometimes down to a few copies. These species have been difficult to detect and quantify
with existing bioanalytical methods due to their insufficient sensitivity, selectivity, and response speed. To
address this challenge, we propose to develop a bipolar electrochemical single entity bioanalyzer, which
will allow us to analyze individual biological species, such as single viruses and circulating tumor exosomes.
The success of this project builds upon the strong expertise of the PI’s group in bipolar electrochemical arrays,
microfabricated sensors, and single entity electroanalysis and has three specific aims. Aim 1 builds the
asymmetric bipolar microelectrode arrays containing 250,000 electrodes and characterizes and optimizes
them for single entity analysis. Aim 2 will synthesize and characterize Janus Pt/silica nanoparticles (NPs) and
use them to label analyte species pre-concentrated onto magnetic microbeads. Aim 3 will build an integrated
analytical platform by combining the bipolar microelectrode array with optical microscopy, characterize and
optimize its analytical performance for single entity bioanalysis of pseudovirus particles and exosomes.
 The proposed analytical platform is innovative and powerful for single entity bioanalysis due to the use
of an optical signal to amplify and read a small electrochemical signal. The use of a large array of 250,000
bipolar microelectrodes and magnetic beads for pre-concentration further enhances the sensitivity, selectivity,
and throughput. Future work will develop a standalone benchtop analytical instrument, which will be useful
for their general use in research and diagnosis involving single entity bioanalysis.

## Key facts

- **NIH application ID:** 10904859
- **Project number:** 5R21GM149994-02
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Bo Zhang
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $217,922
- **Award type:** 5
- **Project period:** 2023-08-01 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10904859

## Citation

> US National Institutes of Health, RePORTER application 10904859, A Bipolar Electrochemical Single Entity Bioanalyzer (5R21GM149994-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10904859. Licensed CC0.

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