title: Site-specific immobilization of gold binding polypeptide on gold nanoparticle-coated graphene sheet for biosensor application.
abstract: The effective and strong immobilization of enzymes on solid surfaces is required for current biological applications, such as microchips, biofuel cells, and biosensors. Gold-binding polypeptide (GBP), a genetically designed peptide, possesses unique and specific interactions with a gold surface, resulting in improved enzyme stability and activity. Herein we demonstrated an immobilization method for biosensor applications through site-specific interactions between GBP-fused organophosphorus hydrolase (GBP-OPH) and gold nanoparticle-coated chemically modified graphene (Au-CMG), showing enhanced sensing capability. A flow injection biosensor was fabricated by using GBP-OPH/Au-CMG to detect paraoxons, a model pesticide, showing higher sensitivity, lower detection limit and better operating stability compared that of OPH/Au-CMG. This strategy, which integrates biotic and abiotic moieties through site-specific interactions, has a great potential for use in biosensing and bioconversion process.
authors.affiliation: Department of Chemical & Biomolecular Engineering, BK21 program, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: MinHo
authors.initials: M
authors.lastname: Yang
authors.forename: Bong Gill
authors.initials: BG
authors.lastname: Choi
authors.forename: Tae Jung
authors.initials: TJ
authors.lastname: Park
authors.forename: Nam Su
authors.initials: NS
authors.lastname: Heo
authors.forename: Won Hi
authors.initials: WH
authors.lastname: Hong
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
mesh_terms: D043303:Aryldialkylphosphatase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D017022:Flow Injection Analysis; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D055767:Immobilized Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D010261:Paraoxon / Q000032:analysis; D010455:Peptides / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D055767:Immobilized Proteins; D010455:Peptides; D010573:Pesticide Residues; D011993:Recombinant Fusion Proteins; D006046:Gold; D006108:Graphite; D043303:Aryldialkylphosphatase; D010261:Paraoxon