# Cold Atmospheric Plasmas in interactions with materials and liquids for biological applications

Franck Clement, Bernard Held, Kristacq Gazeli, Laurent Marlin, Erwan Morel, Fanny Girard-Sahun, Sylvie Blanc, Bruno Grassl, Stephanie Reynaud, Pierre Marcasuzaa, et al.

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## To cite this version:

Franck Clement, Bernard Held, Kristacq Gazeli, Laurent Marlin, Erwan Morel, et al., Cold Atmospheric Plasmas in interactions with materials and liquids for biological applications. 7th International Symposium on Surfaces and Interfaces of Biomaterials, Jul 2019, Québec, Canada. [hal-02191333](https://hal-02191333)

HAL Id: hal-02191333

https://univ-pau.hal.science/hal-02191333

Submitted on 24 Aug 2023

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Distributed under a Creative Commons Attribution 4.0 International License
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# Cold Atmospheric Plasmas in interactions with materials and liquids for biological applications

Franck Clément<fnref n="1" />

[franck.clement@univ-pau.fr](mailto:franck.clement@univ-pau.fr)

In collaboration with: B Held<fnref n="1" />, K Gazeli<fnref n="1" />, L Marlin<fnref n="1" />, E Morel<fnref n="1" />, F Girard<fnref n="1" />, S Blanc<fnref n="1" />, B Grassl<fnref n="1" />, S Reynaud<fnref n="1" />, P Marcasuzaa<fnref n="1" />, C Veclin<fnref n="1" />, I Lebouachera<fnref n="1" />, F Léonardi<fnref n="1" />, Q Hoqui<fnref n="1" />, C Nardin<fnref n="1" />, X Callies<fnref n="1" />, S Arbault<fnref n="2" />, V Badets<fnref n="2" />, P Lefrançois<fnref n="2" />, N Sojic<fnref n="2" />

<figure><img src="image_6.png" /></figure>

Tuesday, July 23, 2019, 11h50-12h30

**Québec City Convention Centre**
1000, boulevard René-Lévesque Est
Québec QC G1R 5T8
Canada

<footnote n="1">¹ Pau University – IPREM UPPA, France</footnote>

<footnote n="2">² Univ. Bordeaux, ISM, CNRS UMR 5255, INP Bordeaux, 33400 Talence, France</footnote>
<figure><img src="image_7.png" /></figure>

Very nice environments

<figure><img src="image_8.png" /></figure>

Wines libraries

<figure><img src="image_9.png" /></figure>

Univ Bordeaux, ENSCPB

<figure><img src="image_10.png" /></figure>

Specialties: GARBURES

béarnaise

<figure><img src="image_11.png" /></figure>

basque

<figure><img src="image_12.png" /></figure>

UPPA - IPREM, Pau

<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>

UPPA - site Côte basque, Montaury

<figure><img src="image_15.png" /></figure>
Why speaking about GARBURES ?

<figure><img src="image_16.png" /></figure>

a bit like ...

**Plasma Components:**

- Neutral particles

- Electrons and Ions

- Electric fields

- Excited Particles: radiative and metastable, radicals, ROS, RNS

- Photons (UV, Visible, IR)

Because GARBURES contains **numerous energy components**: different vegetables (potatoes, pumpkin, leek, turnip, onion, tomato, ...) and different meat (pork, duck, ...)

<figure><img src="image_17.png" /></figure>
**DEFINITION**

COLD PLASMA = WEAKLY IONISED GAS

Produced by **electrical discharges** between two electrodes and by using specific HV power supply

By introducing a dielectric material between the electrodes, and by using pulsed HV power supplies, it is possible to generate cold plasmas at **atmospheric pressure** and temperatures closed to **room temperature**:

COLD ATMOSPHERIC PLASMAS (CAPs)

<figure><img src="image_18.png" /></figure>

<figure><img src="image_19.png" /></figure>

<figure><img src="image_20.png" /></figure>

<figure><img src="image_21.png" /></figure>
# Mechanisms in electrical discharges

## Townsend laws: **Electronic avalanches** in the gap

Ionisation : $A+e^- => A^+ + 2e^-$ ....

Examples of
energy ionisation

<table><thead><tr><td>Molécules</td><td>W<sub>i</sub> (eV)</td></tr></thead><tbody><tr><td>CO<sub>2</sub></td><td>13,7</td></tr><tr><td>N<sub>2</sub></td><td>15,5</td></tr><tr><td>O<sub>2</sub></td><td>12,2</td></tr><tr><td>H<sub>2</sub></td><td>15,4</td></tr><tr><td>H<sub>2</sub>O</td><td>12,6</td></tr></tbody></table>

Two important coefficients depending on the nature of gases and electrodes used

1. Multiplication of charges in the gaseous volume characterized by electronic avalanches and defined by the first Townsend coefficient : $\alpha$ 
   $n=n_0 \cdot \exp(\alpha x)$

2. Multiplication of charges due to secondary emission at the cathode and defined by the second Townsend coefficient : $\gamma$

<figure><img src="image_22.png" /></figure>
# Mechanisms in electrical discharges

After the formation of electronic avalanches, and when the space charge field becomes greater than the applied electric field, the space charge field controls the discharge and its dynamics.

We thus obtain an **ionization wave**, which propagates itself due to the space charge field. This ionization wave is called a **STREAMER**

<figure><img src="image_23.png" /></figure>

The propagation velocity of streamers is higher than electronic avalanche velocity

**10⁵ to 10⁸ cm.s⁻¹**
at atmospheric pressure
Electrons are hot in a cold plasma, allowing the production of numerous excited states

<figure><img src="image_24.png" /><figcaption>Potential energies and diagrams for N₂ and O₂</figcaption></figure>
GUIDED IONIZATION WAVE

<figure><img src="image_25.png" /></figure>

Gazeli, Clément et al., *Possibility of controlling the chemical pattern of He and Ar "guided streamers" by means of N₂ or O₂ additives*,
J. Appl. Phys. **117**, 093302 (2015)

<figure><img src="image_26.png" /></figure>

Gazeli, Clément et al., *A study of helium atmospheric-pressure guided streamers for potential biological applications*,
Plasma Sources Sci. Technol. 22 (2013) 025020 (9pp)
<figure><img src="image_27.png" /></figure>

24h study of the growth of E. coli treated for 1', 2.5', 5' and 10' with He-O₂ plasma

Post treatment time (hours)

SEM Images

<figure><img src="image_28.png" /></figure>

Control

<figure><img src="image_29.png" /></figure>

Treatment Distance: 10 mm Away from the Tube Exit
Q(He-O₂:99-1%)=2 slm, Vc=5 kV, f=10 kHz, rc=1%

<figure><img src="image_30.png" /></figure>

LUXEMBOURG
INSTITUTE
OF SCIENCE
AND TECHNOLOGY

<figure><img src="image_31.png" /></figure>

Clément et al., Study of Reactive Oxygen or/and Nitrogen Species Binding Processes on E. coli Bacteria with Mass Spectrometry Isotopic Nanoimaging, New Journal of Physics 13 (2011) 113040 (12pp)

Duday, Clément et al., NanoSIMS50 analyses of Ar⁶O plasma-treated Escherichia coli bacteria, Plasma Processes and Polymers, vol 10, Issue 10, p 864–879, 2013

Dezest, Clément et al., Oxidative modification and electrochemical inactivation of *Escherichia coli* upon cold atmospheric plasma exposure, PLOS One, 2017, 0173618
## IONIZATION WAVE

<figure><img src="image_32.png" /></figure>

<figure><img src="image_33.png" /></figure>

## Parasites

*Cryptosporidium parvum* oocysts are composed of a capsid containing four infectious sporozoites. Cell integrity is well marked by a luminous crown around the oocysts.

<figure><img src="image_34.png" /></figure>

Drs C. Penny, J-P Cambus, A. Valentin

<figure><img src="image_35.png" /></figure>

LUXEMBOURG
INSTITUTE
OF SCIENCE
AND TECHNOLOGY

<figure><img src="image_36.png" /></figure>

<figure><img src="image_37.png" /></figure>

<figure><img src="image_38.png" /></figure>
IONIZATION WAVE

<figure><img src="image_39.png" /></figure>

Lack of mechanisms understanding

What are the interactions?

<figure><img src="image_40.png" /></figure>

ATMOSPHERIC PLASMA

Air
environment

Liquid
environment

LIVING SYSTEMS
PLASMA-AIR and PLASMA-LIQUID INTERFACES

<figure><img src="image_41.png" /></figure>

phD UPPA
Girard F. Pau
# IONIZATION WAVE in interaction with air and water environments

## Possible mechanisms

<table><thead><tr><th></th><th>In the gas</th><th>In the liquid<br>(PBS: phosphate buffer saline)</th></tr></thead><tbody><tr><td>H<sub>2</sub>O<sub>2</sub></td><td>HO° + HO° → H<sub>2</sub>O<sub>2</sub><br>N<sub>2</sub> (A<sup>3</sup>Σ<sub>u</sub><sup>+</sup>) + H<sub>2</sub>O<sub>(g)</sub> → HO° + H° + N<sub>2</sub><br>N<sub>2</sub>(B<sup>3</sup>π) → N<sub>2</sub> (A<sup>3</sup>Σ<sub>u</sub><sup>+</sup>) + hν<br>N<sub>2</sub> (FPS) observed in the plasma: N<sub>2</sub>(A)</td><td>HO° + HO° → H<sub>2</sub>O<sub>2</sub></td></tr><tr><td>NO<sub>2</sub><sup>-</sup></td><td>HO° + NO° + M → HNO<sub>2</sub> + M<br>M : collision partner</td><td>HNO<sub>2</sub> + HPO<sub>4</sub><sup>2-</sup> ⇌ NO<sub>2</sub><sup>-</sup> + H<sub>2</sub>PO<sub>4</sub><sup>-</sup></td></tr><tr><td>NO<sub>3</sub><sup>-</sup></td><td>NO<sub>2</sub><sup>°</sup> + HO° + M → HNO<sub>3</sub> + M*<br>...</td><td>HNO<sub>3</sub> ⇌ H<sup>+</sup> + NO<sub>3</sub><sup>-</sup><br>...</td></tr></tbody></table>

<figure><img src="image_42.png" /></figure>
# GAS-LIQUID INTERACTION

By using a shielding gas device !

<figure><img src="image_43.png" /></figure>

Girard, Clément et al.
Phys. Chem. Chem. Phys.
2018, 20, 9198-9210
Maximum of excited levels of He
for air mixture

<figure><img src="image_44.png" /></figure>
When increasing O₂ %, rapid decrease of NO and slower decrease of N₂ (SPS, FPS) and N₂⁺ (FNS)

<figure><img src="image_45.png" /></figure>
When increasing O₂ %, decrease of OH and H, increase of O and O₂⁺

<figure><img src="image_46.png" /></figure>
GAS-LIQUID INTERACTION

<figure><img src="image_47.png" /></figure>

2ml PBS exposed

Girard, Clément et al.
Phys. Chem. Chem. Phys. 2018, 20, 9198-9210

Electrochemistry

<figure><img src="image_48.png" /></figure>

Absorption spectroscopy

<figure><img src="image_49.png" /></figure>
GAS-LIQUID INTERACTION

<figure><img src="image_50.png" /><figcaption>$NO_2^-$ correlated with pH variation in buffered solution (PBS)</figcaption></figure>

Measured by
Electrochemistry
and Absorption
spectroscopy
# GAS-LIQUID INTERACTION

By changing pH, it is possible to measure unstable Species in solution

pH 12
Buffered solution
2ml PBS

PEROXYNITRITE

Measured by
Absorption
spectroscopy

<figure><img src="image_51.png" /></figure>

Girard, Clément et al.
Phys. Chem. Chem. Phys. 2018, 20, 9198-9210
# GAS-LIQUID INTERACTION

By changing pH, it is possible to measure
unstable Species in solution

ANION
SUPEROXYDE $O_2^°-$

<figure><img src="image_52.png" /></figure>

Measured by
Electrochemistry

$E (V vs. Ag/AgCl)$

Collab. ENSCBP Bordeaux : S. Arbault, V. Badets, P. Lefrançois

After exposition to
plasma:

1- $O_2^°-$ detected in PBS
at pH 11

2- $O_2^°-$ is fully
converted to $H_2O_2$
after adjustment of
pH to 7.4
GAS-LIQUID INTERACTION

**Helium** plasma produces ROS and RNS
including:

☑ $H_2O_2$

Abs. Spectroscopy

Electrochemistry

(20-30 µM.min⁻¹)*

☑ $O_2^{\ominus}$

Electrochemistry (not quantified)

☑ $ONOO^{-}$

Abs. Spectroscopy

(0.2-1.2 µM.min⁻¹)*

☑ $NO_2^{-}$

Abs. Spectroscopy

Electrochemistry

(30-45 µM.min⁻¹)*

☑ $NO_3^{-}$

Abs. Spectroscopy

(30-45 µM.min⁻¹)*

* With $N_2$ as shielding gas

<figure><img src="image_53.png" /></figure>

<figure><img src="image_54.png" /></figure>
# GAS-LIQUID INTERACTION in situ, during plasma exposure

**Electrical fields** implied in ionization waves are in the order of magnitude of some $10\text{kV.cm}^{-1}$

Sretenovic, G. et al., J.Appl.Phys. 452 2017, 121 (12), 123304.

Razavizadeh, S. et al., Plasma Sources Sci. 454 Technol. 2018, 27 (7), 075016.

**Difficulties** to measure very low faradaic currents, in the nA range, in the presence of high electric fields used for plasma formation

<figure><img src="image_55.png" /></figure>

Reactive oxygen species generated by cold atmopsheric plasmas in aqueous solution: Successful Electrochemical Monitoring in Situ under a High Voltage System, Girard, Clément et al., Analytical Chemistry, 2019

https://doi.org/10.1021/acs.analchem.9b01912
# GAS-LIQUID INTERACTION in situ, during plasma exposure

<figure><img src="image_56.png" /><figcaption>Black Pt working electrode
(enhanced selectivity and sensibility)</figcaption></figure>

<figure><img src="image_57.png" /></figure>

## Different types of shielded electrodes used during plasma exposure

WE = Platinized Pt disk (25 µm Ø, 37.5 µC)

Ref = Ag/AgCl wire

CE = Pt wire

<figure><img src="image_58.png" /></figure>
GAS-LIQUID INTERACTION in situ, during plasma exposure

<figure><img src="image_59.png" /></figure>

<figure><img src="image_60.png" /></figure>

Possibility to follow long-lived and short-lived RONS
produced in PBS during plasma exposure
# IONIZATION WAVE in interaction with materials

## Lack of mechanisms understanding

<figure><img src="image_61.png" /></figure>

What are the
interactions?

<figure><img src="image_62.png" /></figure>

ATMOSPHERIC PLASMA

MATERIALS

<figure><img src="image_63.png" /></figure>

https://en.wikipedia.org/wiki/Biomaterial_Surface Modifications

Numerous applications

Cleaning

Etching

Functionalization

Coating

Sterilization

Enhanced cell growth

...
These atmospheric plasmas can be used for polymer surface treatments ...

<figure><img src="image_64.png" /><figcaption>Exposition of Thermoplastic Polyurethane (TPU)
Wettability analyses of the surfaces exposed</figcaption></figure>

Plasma He + 1% O₂
Different types of polymers exposed...

<table><thead><tr><th>PE</th><th>PP</th><th>PS</th><th>PET</th><th>PLA</th></tr></thead><tbody><tr><td>(H-C-H-C-H)n</td><td>[CH3]n</td><td>[C6H5-C-H-C-H]n</td><td>([O-C6H5-C(O)-CH2-C(O)-CH2]n)</td><td>[CO2(O)CH2-O]n</td></tr></tbody></table>

<figure><img src="image_65.png" /></figure>

<figure><img src="image_66.png" /></figure>

<figure><img src="image_67.png" /></figure>

<figure><img src="image_68.png" /></figure>

<figure><img src="image_69.png" /><figcaption>He - N2 CAP</figcaption></figure>

<figure><img src="image_70.png" /><figcaption>He CAP</figcaption></figure>

<figure><img src="image_71.png" /><figcaption>He - O2 CAP</figcaption></figure>

<figure><img src="image_72.png" /></figure>
# IR-ATR analyses of PLA substrates exposed

<figure><img src="image_73.png" /></figure>

## Surface Functionalization ?

## Surface Degradation ?
Another example
IR-ATR analyses of PET substrates exposed

<figure><img src="image_74.png" /></figure>

Surface Functionalization ?
Surface Degradation ?
Another example
IR-ATR analyses of PP substrates exposed

<figure><img src="image_75.png" /></figure>
Another example
IR-ATR analyses of PP substrates exposed

<figure><img src="image_76.png" /></figure>
<figure><img src="image_77.png" /></figure>

IR ATR is a simple method to follow qualitatively surface oxidation

As well as wetability analyses

<figure><img src="image_78.png" /><figcaption>Before plasma exposure</figcaption></figure>

<figure><img src="image_79.png" /><figcaption>After plasma exposure</figcaption></figure>

But ...

chemical characterizations are needed (XPS)

Surface aging must be controlled, which is linked to the gaseous media in which the samples are stored!

Work in progress...
Steel processing tests

<figure><img src="image_80.png" /></figure>

<figure><img src="image_81.png" /></figure>

<figure><img src="image_82.png" /></figure>

The plasma bounces on the surface

First wetability tests
Water drop spreading

Cleaning ?

Work in progress...

<figure><img src="image_83.png" /></figure>

<figure><img src="image_84.png" /></figure>
CONCLUSION

Ionization waves produced at atmospheric pressure are very interesting processes
for the production of reactive species usefull for biomedical applications

Discharges mechanisms have to be studied for the production of
these reactive species: charges, radicals and excited states, photons

Electrochemistry methods are very usefull to follow the production
of chemical species produced in liquids during plasma exposures

The control of the environments (gas and liquid) is capital for a
better understanding of the interactions mechanisms between
plasmas and liquids or solid materials
Finally

« Garbures » are complex to analyse and difficult to reproduce, but we love to cook and we can sometimes find new recipes !

<figure><img src="image_85.png" /><figcaption>le ragoût de pattes de cochon
« pig's leg stew »</figcaption></figure>

<figure><img src="image_86.png" /></figure>

<figure><img src="image_87.png" /><figcaption>The « POUTINE »</figcaption></figure>

Merci

To the organising committee
To Cora Roy for her help and
of course to Diego Mantovani

<figure><img src="image_88.png" /></figure>

and THANK YOU FOR YOUR ATTENTION