Nano-texturing of poly(methyl methacrylate) polymer using plasma processes and applications in wetting control and protein adsorption

In this work, we demonstrate fabrication of random columnar/filamented-like, low and high-aspect ratio micro or nano-structures based on O-2 plasma-induced roughening (nano-texturing) of poly(methyl methacrylate) (PMMA). Plasma etching duration and conditions ensured absolute control of the topography height (37-2400 nm) and surface chemistry. The effect of topography and ageing on surface wettability and protein adsorption capacity was investigated. Conditions (plasma treatment and ageing) are sought for maximum and uniform protein adsorption on nanotextured PMMA surfaces. Specifically, adsorption of biotinylated-BSA was found to increase with plasma duration. A 2-4 times (depending on the protein concentration) increase was observed on aged surfaces prepared following 5-60 min O-2 plasma treatment compared to untreated PMMA surfaces. Highly homogeneous protein microspots on such optimized plasma-nanostructured surfaces are also shown. (C) 2008 Elsevier B.V. All rights reserved.