title: DNA-directed protein immobilization on mixed self-assembled monolayers via a streptavidin bridge.
abstract: The simultaneous detection of multiple analytes is an important consideration for the advancement of biosensor technology. Currently, few sensor systems possess the capability to accurately and precisely detect multiple antigens. This work presents a simple approach for the functionalization of sensor surfaces suitable for multichannel detection. This approach utilizes self-assembled monolayer (SAM) chemistry to create a nonfouling, functional sensor platform based on biotinylated single-stranded DNA immobilized via a streptavidin bridge to a mixed SAM of biotinylated alkanethiol and oligo(ethylene glycol). Nonspecific binding is minimized with the nonfouling background of the sensor surface. A usable protein chip is generated by applying protein-DNA conjugates which are directed to specific sites on the sensor chip surface by utilizing the specificity of DNA hybridization. The described platform is demonstrated in a custom-built surface plasmon resonance biosensor. The detection capabilities of a sensor using this protein array have been characterized using human chorionic gonadotropin (hCG). The platform shows a higher sensitivity in detection of hCG than that observed using biotinylated antibodies. Results also show excellent specificity in protein immobilization to the proper locations in the array. The vast number of possible DNA sequences combine with the selectivity of base-pairing makes this platform an excellent candidate for a sensor capable of multichannel protein detection.
authors.affiliation: Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Jon
authors.initials: J
authors.lastname: Ladd
authors.forename: Christina
authors.initials: C
authors.lastname: Boozer
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Yu
authors.forename: Shengfu
authors.initials: S
authors.lastname: Chen
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 / Q000379:methods; D001710:Biotin / Q000737:chemistry; D006063:Chorionic Gonadotropin / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D006801:Humans; D007103:Immobilization; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods; D013499:Surface Properties
chemical_list: D000906:Antibodies; D006063:Chorionic Gonadotropin; D001710:Biotin; D004247:DNA; D019809:Streptavidin