Polymer-Based Photoactive Surface for the Efficient Immobilization of Nanoparticles, Polymers, Graphene and Carbohydrates

• Main Author: Yuwen, Jing
• Format: Others
• Published: PDXScholar 2011
• Subjects: Covalent immobilization; Polymer-based photocoupling surface; Perfluorophenyl azide; Polyallyamine; Polymers > Surfaces; Surfaces (Technology); Nanotechnology
• Online Access: https://pdxscholar.library.pdx.edu/open_access_etds/413; https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1412&context=open_access_etds

This thesis focuses on developing a new photocoupling surface, base on polyallyamine (PAAm), to increase the efficiency of the photocoupling agent perfluorophenyl azide (PFPA) in the immobilization of nanoparticles, carbohydrates and graphene. Extensive studies have been carried out in our lab on the covalent immobilization of polymers and graphene using PFPA-functionalized surfaces. Here we show that PAAm-based PFPA surface can be used to efficiently immobilize not only graphene and polymers but also nanomaterials and small molecules. This was accomplished by first silanizing silicon wafers with PFPA-silane followed by attaching a thin film of PAAm by UV radiation. Treating the PAAm surface with N-hydroxysuccinimide-derivatized PFPA (PFPA-NHS) yielded the PAAm-PFPA surface. The functionalized surfaces were characterized by ellipsometry (layer thickness), contact angle (surface tension), and ATR-FTIR. The PAAm surface was further characterized by determining the density of amino groups on the surface. The PAAm-PFPA surfaces were subsequently used to covalently immobilize polymers, nanomaterials, carbohydrates and graphene by a simple procedure of coating the molecules or materials on the PAAm-PFPA surface followed by UV irradiation. The resulting surfaces were characterized using ellipsometry, AFM, optical microscopy. The attached carbohydrates were further evaluated using lectins, i.e., carbohydrate-binding proteins.