Plasma-treated polyethylene surfaces for improved binding of active protein

The use of plasma immersion ion implantation (PIII) to prepare polyethylene surfaces for binding active proteins is investigated. The PIII surface treatment significantly improves the density of active HRP bound to the surface after incubation in buffer containing the protein. The retention of enzyme activity on the PIN-treated surfaces is greatly improved as compared to both untreated controls and surfaces exposed to the plasma without the PIII treatment. A nitrogen PHI treatment produced surfaces with the best retention. of protein activity. Oxidation of the ion-damaged surface and the formation of a carbonized subsurface are believed to be responsible for the observed protein binding properties.