1 research outputs found
A comparative study of biomolecule and polymer surface modifications by a surface microdischarge
Cold atmospheric plasma (CAP) sources are attractive sources of reactive species with
promising industrial and biomedical applications, but an understanding of underlying
surface mechanisms is lacking. A kHz-powered surface microdischarge (SMD) operating with
N2/O2 mixtures was used to study the biological deactivation of
two immune-stimulating biomolecules: lipopolysaccharide (LPS) and peptidoglycan (PGN),
found in bacteria such as Escherichia coli and Staphylococcus
aureus, respectively. Model polymers were also studied to isolate specific
functional groups. Changes in the surface chemistry were measured to understand which
plasma-generated species and surface modifications are important for biological
deactivation. The overall goal of this work is to determine which effects of CAP treatment
are generic and which bonds are susceptible to attack. CAP treatment deactivated
biomolecules, oxidized surfaces, and introduced surface bound NO3. These effects can be
controlled by the N2 fraction in O2 and applied voltage and vary among different target
surfaces. The SMD was compared with an Ar/O2/N2-fed kHz-powered atmospheric pressure plasma jet and
showed much higher surface modifications and surface chemistry tunability compared to the
jet. Possible mechanisms are discussed and findings are compared with recent computational
investigations. Our results demonstrate the importance of long-lived plasma-generated
species and advance an atomistic understanding of CAP-surface interactions