Surface analysis of protein-resistant, plasma-polymerized ethylene glycol thin films

Poly(ethylene glycol) (PEG) has been widely used in biomedical applications because of its protein‐resistant and nontoxic properties. In this study, a plasma‐polymerized ethylene glycol (PPEG) thin film was deposited on a substrate using a capacitively coupled plasma chemical vapour deposition (CCP‐CVD) method with various plasma powers and ethylene glycol as a precursor. The surfaces of the PPEG thin films were characterized using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) along with a principal component analysis (PCA), and XPS. We confirmed that the PPEG thin film deposited at low plasma power closely resembles PEG polymers in terms of surface chemical composition and protein‐resistant property. To make patterned surfaces with protein‐resistant property for proteins, a PPEG thin film was first uniformly deposited on a glass slide and patterns were produced on the PPEG coated surface by depositing a plasma‐polymerized amine film through a metal shadow mask. When we spotted proteins on the patterned surface, they were immobilized only onto the plasma‐polymerized amine areas but not onto the PPEG areas. These results show that PPEG surfaces would be useful for the construction of various protein arrays. Copyright © 2010 John Wiley & Sons, Ltd.