title: Photopatterned thiol surfaces for biomolecule immobilization.
abstract: The ability to pattern small molecules and proteins on artificial surfaces is of importance for the development of new tools including tissue engineering, cell-based drug screening, and cell-based sensors. We describe here a novel "caged" thiol-mediated strategy for the fabrication of planar substrates patterned with biomolecules using photolithography. A thiol-bearing phosphoramidite (3-(2'-nitrobenzyl)thiopropyl (NBTP) phosphoramidite) was synthesized and coupled to a hydroxyl-terminated amorphous carbon substrate. A biocompatible oligo(ethylene glycol) spacer was used to resist nonspecific adsorption of protein and DNA and enhance flexibility of attached biomolecules. Thiol functionalities are revealed by UV irradiation of NBTP-modified surfaces. Both the surface coupling and photodeprotection were monitored by Polarization Modulation Fourier Transform Infrared Reflection Absorption Spectroscopy (PM-FTIRRAS) and X-ray Photoelectron Spectroscopy (XPS) measurements. The newly exposed thiols are chemically very active and react readily with a wide variety of groups. A series of molecules including biotin, DNA, and proteins were attached to the surfaces with retention of their biological activities, demonstrating the utility and generality of the approach.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Chen
authors.forename: Lloyd M
authors.initials: LM
authors.lastname: Smith
mesh_terms: D001483:Base Sequence; D001710:Biotin / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics; D055767:Immobilized Proteins / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry; D055668:Photochemical Processes; D013055:Spectrophotometry, Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D004277:DNA, Single-Stranded; D055767:Immobilized Proteins; D009943:Organophosphorus Compounds; D013438:Sulfhydryl Compounds; C434331:phosphoramidite; D001710:Biotin