title: DNA directed protein immobilization on mixed ssDNA/oligo(ethylene glycol) self-assembled monolayers for sensitive biosensors.
abstract: A stable and versatile biosensor surface is prepared by site-directed immobilization of protein-DNA conjugates onto a mixed self-assembled monolayer (SAM) composed of ssDNA thiols and oligo(ethylene glycol) (OEG) terminated thiols. The protein conjugates consist of an antibody chemically linked to a ssDNA target with a sequence complementary to the surface-bound ssDNA probes and are immobilized on the surface via sequence-specific hybridization. Compared to standard antibody immobilization techniques, this approach offers many advantages. The exceptional specificity of DNA hybridization combined with the diversity of potential sequences makes this platform perfect for multichannel sensors. Once a surface is patterned with the appropriate probe sequences, sequence-specific hybridization will sort out the target conjugates and direct them to the appropriate spots on the surface. In addition, the DNA SAMs are very stable and well suited to recycling by dehybdridization of the conjugates from the surface-bound probes. In this work, we demonstrate the specificity, sensitivity, and convenience of using protein-DNA conjugates to convert a DNA/OEG SAM surface into a biosensor surface and apply this platform to the detection of human chorionic gonadotropin using surface plasmon resonance.
authors.affiliation: Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Boozer
authors.forename: Jon
authors.initials: J
authors.lastname: Ladd
authors.forename: Shengfu
authors.initials: S
authors.lastname: Chen
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Yu
authors.forename: Jiri
authors.initials: J
authors.lastname: Homola
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Jiang
mesh_terms: D000906:Antibodies / Q000737:chemistry*; D000937:Antigen-Antibody Reactions; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D006063:Chorionic Gonadotropin / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006801:Humans; D008567:Membranes, Artificial; D009113:Muramidase / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D011485:Protein Binding; D012680:Sensitivity and Specificity; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000906:Antibodies; D006063:Chorionic Gonadotropin; D004277:DNA, Single-Stranded; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D011092:Polyethylene Glycols; D009113:Muramidase