CVD-based Polymer Substrates for Spatially-resolved Analysis of Protein Binding by Imaging Ellipsometry

摘要

Biomolecular interactions between proteins and synthetic surfaces impact diverse biomedical fields. Simple, quantitative, label-free technologies for the analysis of protein adsorption and binding of biomolecules are thus needed. Here, we report the use of a novel type of substrate, poly-p-xylylenes coating prepared by chemical vapor deposition (CVD) polymerization, for surface plasmon resonance enhanced ellipsometry (SPREE) studies and assess the reactive coatings as spatially-resolved biomolecular sensing arrays. Prior to use in binding studies, reactive coatings were fully characterized by Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS), and ellipsometry. As a result, chemical structure, thickness, and homogenous coverage of the substrate surface were confirmed for a series of CVD-coated samples. Subsequent SPREE imaging and fluorescence microscopy indicated that the synthetic substrates supported detectable binding of a cascade of biomolecules. Moreover, analysis revealed a useful thickness range for CVD films in the assessment of protein and/or antigen-antibody binding via SPREE imaging. With a variety of functionalized end groups available for biomolecule immobilization and ease of patterning, CVD thin films are useful substrates for spatially-resolved, quantitative binding arrays.