# A ratiometric fluorescent sensor array for bacterial pathogen investigation

> **NIH NIH R01** · UNIVERSITY OF NEBRASKA MEDICAL CENTER · 2022 · $343,125

## Abstract

PROJECT SUMMARY
Rapid and reliable identification of pathogenic microorganisms is critical for efficient protection of public health
and safety. The high versatility of bacterial pathogens allows them to survive in various environments and the
emergence of multidrug-resistant species pose a particularly severe threat. Current identification of bacteria
largely relies on phenotypic characterization, Gram staining, culturing, and PCR. However, these techniques are
time consuming and require trained laboratory personnel and expensive equipment. Thus, there is a tremendous
need to develop a simple and efficient bacterial identification method. Recently, a sensing strategy has emerged
that utilizes chemicals that do not specifically interact with a particular analyte, but instead react to the general
chemical microenvironment. By using a combination of these chemicals, response patterns can be modelled for
highly sensitive and specific detection of chemical and biological analytes. These barcoding arrays or so-called
“chemical noses” often rely upon absorbance or fluorescence intensity as the output, which makes them highly
susceptible to the sensor concentration. Innovative methods are required to harness the versatility of chemical
barcodes and simultaneously eliminate the pitfalls of concentration dependence. The approach we will employ
here is to generate chemical barcodes that come from fluorophores with a ratiometric response, i.e. ratio of
fluorescence intensities at different wavelengths that depend on the local chemical environment. Moreover, our
recent investigations suggest that dye entrapment in polysaccharide-derived nanoparticles will result in sensors
that are stable and able to interact with Gram positive and Gram negative bacteria under various conditions.
Thus, the overarching goal of this proposal is to design, synthesize, characterize and evaluate a new sensor
array that is based on environment-sensitive ratiometric dyes. The proposed approach will provide a versatile
platform for express identification of pathogenic microorganisms in a clinical laboratory setting and in the field.
We hypothesize that environment-sensitive fluorescent dyes possessing various substituents will exhibit different
spectral responses upon interaction with bacterial cell walls. Being combined into an array, these dyes will produce
a unique bar code-like spectral fingerprint for various bacteria, enabling their fast detection and identification. This
hypothesis will be tested in three aims that are at the interface of chemistry and microbiology. The first aim is to
develop a fluorescent sensor platform that provides a specific multiparametric spectral response with different
bacteria. The second aim is to investigate the interactions of the dyes with bacteria to optimize the reproducibility
of the sensor response. The third aim is to implement the sensor array as a research tool for probing of bacterial
cell envelope homeostasis. Achieving these aims will...

## Key facts

- **NIH application ID:** 10425245
- **Project number:** 5R01EB027662-04
- **Recipient organization:** UNIVERSITY OF NEBRASKA MEDICAL CENTER
- **Principal Investigator:** Aaron M. Mohs
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $343,125
- **Award type:** 5
- **Project period:** 2019-07-08 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10425245

## Citation

> US National Institutes of Health, RePORTER application 10425245, A ratiometric fluorescent sensor array for bacterial pathogen investigation (5R01EB027662-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10425245. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*