title: Facile photoimmobilization of proteins onto low-binding PEG-coated polymer surfaces.
abstract: Immobilization of proteins onto polymer surfaces usually requires specific reactive functional groups. Here, we show an easy one-step method to conjugate protein covalently onto almost any polymer surface, including low protein-binding poly(ethylene glycol) (PEG), without the requirement for the presence of specific functional groups. Several types of proteins, including alkaline phosphatase, bovine serum albumin, and polyclonal antibodies, were photoimmobilized onto a PEG-coated polymer surface using a water-soluble benzophenone as photosensitizer. Protein functionality after immobilization was verified for both enzymes and antibodies, and their presence on the surface was confirmed by X-ray photoelectron spectroscopy (XPS) and confocal fluorescence microscopy. Conjugation of capture antibody onto the PEG coating was employed for a simplified ELISA protocol without the need for blocking uncoated surface areas, showing ng/mL sensitivity to a cytokine antigen target. Moreover, spatially patterned attachment of fluorescently labeled protein onto the low-binding PEG-coated surface was achieved with a projection lithography system that enabled the creation of micrometer-sized protein features.
authors: Department of Micro- and Nanotechnology, DTU Nanotech, Technical University of Denmark , Ørsteds Plads 345E, DK-2800 Kgs. Lyngby, Denmark.
authors: Esben Kjær Unmack
authors: EK
authors: Larsen
authors: Morten Bo Lindholm
authors: MB
authors: Mikkelsen
authors: Niels B
authors: NB
authors: Larsen
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry; D000818:Animals; D000906:Antibodies / Q000737:chemistry; D002417:Cattle; D055767:Immobilized Proteins / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000906:Antibodies; D055767:Immobilized Proteins; D011108:Polymers; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D000469:Alkaline Phosphatase