Removal of Model Proteins Using Beams of Argon Ions, Oxygen Atoms and Molecules: Mimicking the Action of Low‐Pressure Ar/O₂ ICP Discharges

Abstract

The action of Ar/O2 plasmas with proteins is mimicked by employing a particle beam experiment with individually controllable and absolutely calibrated sources of O atoms/O2 molecules and of argon ions. It is demonstrated that beams of thermal O atoms and of O2 molecules with fluences up to jO = 8.6 × 1018 cm−2 and jO2 = 5.4 × 1020 cm−2 have no measurable effect on the proteins at room temperature, whereas the combination of an O/O2 beam and of an 100 eV Ar+ ion beam induces very efficient protein removal, which is accompanied by a significant increase of their surface roughness. These observations are attributed to the process of chemical sputtering caused by the simultaneous impact of incident radicals and energetic ions.

Elimination of Biological Contaminations from Surfaces by Plasma Discharges: Chemical Sputtering

“…[56] It has been demonstrated that neither H atoms nor O atoms alone have the capability to cause significant erosion of the treated biological systems at room temperature as demonstrated by 2D ellipsometric D-angle maps of protein samples (untreated and after exposure to O and H beams for 60 min in Figure 7) and by SEM images of B. atrophaeus spores exposed to an O-atom beam for 60 min (Figure 8 b).…”

Generation and loss of reactive oxygen species in low-temperature atmospheric-pressure RF He + O2 + H2O plasmas

“…A large number of plasma sources and biological targets have been investigated to date and there is growing amount of literature that suggests that for low-temperature atmospheric-pressure plasmas the interaction with biological targets is mainly chemistry driven [3,4,5]. UV radiation and physical etching observed in low-pressure plasma treatments [6,7] do not seem to play a dominant role at atmospheric pressure. Indeed the flux of neutral ROS to the target is orders of magnitude larger than that of ions and at atmospheric pressure the ion energy is generally small due to the large collisionality of the sheaths [8].…”

Low-pressure water vapour plasma treatment of surfaces for biomolecules decontamination

“…Chemical sputtering was already proven to be a solid framework for sterilization and biomolecules etching data interpretation [27,[42][43][44]. Plasma characterization described in the previous section provides a dataset for reactive particle fluxes, which are proportional to the bulk densities of radical atoms and molecules as measured by actinometry.…”