# Direct bioelectronic detection of SARS-CoV-2 from saliva using single-molecule field-effect transistor array

> **NIH NIH R44** · QUICKSILVER BIOSCIENCES, INC. · 2022 · $447,801

## Abstract

Direct bioelectronic detection of SARS-CoV-2 from saliva
 using single-molecule field-effect transistor array
 Nucleic acid tests have become the gold-standard for diagnostic testing for COVID-19, usually performed
in specialized laboratories. Most are based on reverse-transcription quantitative polymerase chain reaction
(qRT-PCR). The time required for specimen transport and processing results in a turnaround time that is typi-
cally several days. The few rapid (<1 hour) point-of-care (POC) tests are more expensive, still require sample
preparation and specialized reagents, and do not have the throughput needed for population surveillance. Di-
rect testing for the virus, which also reduces requirements for multiple reagents, is a necessary step to improv-
ing diagnostic testing. While four such antigen tests have been approved for detection of SARS-CoV-2 based
on immunoassays to the N protein, sensitivity is limited and no quantitation of viral load is possible.
 We will address this gap by using DiagnostikosTM, an in-development rapid POC platform for direct, real-
time, multiplexed, quantitative bioelectronic detection of biomolecules that employs an all-electronic detection
device that functions at the single-molecule level. These single-molecule field-effect transistors (smFETs) are
arrayed on a complementary metal-oxide-semiconductor (CMOS) integrated circuit chip. Chips will interface
with an envisioned USB-stick-form-factor reader device. Robust single-domain antibodies, known as nanobod-
ies and immobilized on these devices, are used for sensitive detection of viral particles and viral debris. The
use of multiple nanobodies for a single protein and nanobodies for different proteins in a single assay allows
for significant improvements in specificity. Nanobodies will be specific for one or more of the four major struc-
tural proteins in SARS-CoV-2; the nucleocapsid (N) protein engulfing the viral RNA, the spike (S) protein, the
membrane (M) protein and the envelope (E) protein. No sample preparation or specialized reagents are re-
quired for detection, and the device will be designed to operate with saliva, which has very recently been
shown to be a reliable medium for detecting SARS-CoV-2. Individual sensor chips can be manufactured at a
cost of $35. With the addition of other nanobodies, these large dense arrays can also allow detection of many
pathogens in a single test.
 In this Direct-To-Phase-2 SBIR program we will pursue several key innovations that are required to make
such a platform possible, including isolation of nanobodies for key structure proteins of SARS-CoV-2 (Specific
Aim 1), development of the smFET platform for antigen detection (Specific Aim 2), development of large
CMOS arrays of these smFET devices (Specific Aim 3), and verification of detection in increasingly complex
samples up to and including clinical samples (Specific Aim 4). This project is a partnership between university
researchers who developed the smFET t...

## Key facts

- **NIH application ID:** 10320987
- **Project number:** 4R44DE030841-02
- **Recipient organization:** QUICKSILVER BIOSCIENCES, INC.
- **Principal Investigator:** Kenneth L Shepard
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $447,801
- **Award type:** 4N
- **Project period:** 2020-12-21 → 2024-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10320987

## Citation

> US National Institutes of Health, RePORTER application 10320987, Direct bioelectronic detection of SARS-CoV-2 from saliva using single-molecule field-effect transistor array (4R44DE030841-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10320987. Licensed CC0.

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