Biodeactivation of Lipopolysaccharide Correlates with Surface‐Bound NO₃After Cold Atmospheric Plasma Treatment

Abstract

Cold atmospheric plasma (CAP) treatment of biological surfaces results in important changes of biological functions, but little knowledge on specific surface‐chemical changes is available. We measured surface‐bound NO 3 on polymer and biomolecular films after CAP treatment. An O 2 /N 2 ‐based surface microdischarge was used to deactivate lipopolysaccharide (LPS), an immune‐stimulating biomolecule found in Gram negative bacteria. The observed LPS biodeactivation was highest for low N 2 concentrations in O 2 , increased roughly linearly with surface NO 3 , and then saturated. NO 3 was also observed after treatment by a very different source: an atmospheric pressure plasma jet operating with an Ar carrier gas. Thus, NO 3 formation is a generic surface chemical modification of these materials by CAP sources.