# Use of polyaniline (PAni) for the detection and identification of bacteria in human whole blood by electrochemistry

Thibaut Babin, Laura Bernard, Tommy Dedole, Pierre Bouvet, Stephan Pissot, Pierre Marcoux, Maxime Gougis, Pascal Mailley

► To cite this version:

Thibaut Babin, Laura Bernard, Tommy Dedole, Pierre Bouvet, Stephan Pissot, et al.. Use of polyaniline (PAni) for the detection and identification of bacteria in human whole blood by electrochemistry. EMRS Spring meeting, May 2025, Strasbourg, France. cea-05519757

HAL Id: cea-05519757

https://cea.hal.science/cea-05519757v1

Submitted on 19 Feb 2026

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## CONTEXT

**Human blood** = physiological liquid, normally completely sterile.

**Blood infections** = repetition and/or prolongation of incursion of micro-organisms in the bloodstream.

Every year in the world :

* 30 million bloodstream infections

* More than one million deaths (2019) from antibiotic-resistant bacteria

> "We estimated that unless action is taken, the burden of deaths from AMR could balloon to 10 million lives each year by 2050"

Jim O'Neill. Tackling Drug-Resistant Infections
Globally: Final Report and Recommendations.
2016.

<caption>Fast effective antimicrobial therapy increases survival chances</caption>

Adapted from Kumar A, et al. Crit Care Med. 2006;34(6):1589-96. (15)

<figure><img src="image_3.png" /></figure>

Urgent need for fast, accurate, cheap diagnostic tools!

## PAni ELECTROCHEMICAL BEHAVIOR

**Objective.** Understanding the cause of electrochemical fingerprints.

→ **EIS analysis** in human whole blood during *E. coli* growth and negative sample **at the OCP**.

<figure><img src="image_4.png" /></figure>

In the case of bacterial growth, the impedance of polyaniline drops after the potential peak.

<figure><img src="image_5.png" /></figure>

**Analysis at 0.1 Hz.** Modulus of impedance drops during bacterial growth and then increases → seems to indicate the presence of molecules, in the vicinity of the electrode, favoring charge transfer.

## BACTERIA DETECTION BY OCP

**Principle.** Bacterial growth in a vial → CO2 production → pH ↗. A pH sensor should detect bacterial growth in a blood culture vial.

<figure><img src="image_6.png" /><figcaption>pH detection of *E. coli* growth in human whole blood by OCP.</figcaption></figure>

<figure><img src="image_7.png" /></figure>

## BACTERIAL IDENTIFICATION

By potentiometry (with derivative of the potential) :

* Detection of bacterial growth = potential ↗ means pH ↗

* Unexpected behavior after detection = potential ↗ but pH stable

* **Electrochemical fingerprint** by derivative

<figure><img src="image_8.png" /><figcaption>Electrochemical signatures data base</figcaption></figure>

Each bacteria as a unique electrochemical fingerprint !
Could be used for identification (by machine learning).

## DISCUSSION & PERSPECTIVES

* ✓ Microbial growth detection by measuring Pani OCP in whole blood.

* ✓ Bacterial identification without any specific probe (DNA, antibody...).

* ✓ Highlighting the importance of microbial biofouling for this method.

* ➤ **To be carried out:** electrochemical study of bacterial biofilms.