title: Covalent attachment of biomacromolecules to plasma-patterned and functionalized carbon nanotube-based devices for electrochemical biosensing.
abstract: The interface between biomacromolecules and carbon nanotubes (CNTs) is of critical importance in developing effective techniques that provide CNTs with both biomolecular recognition and signal transduction through immobilization. However, the chemical inertness of CNT surfaces poses an obstacle to wider implementation of CNTs in bioanalytical applications. In this paper, we present a review of our recent research activities related to the covalent attachment of biomacromolecules to plasma-patterned and functionalized carbon nanotube films and their application to the fabrication of electrochemical biosensing devices. The SWCNT films were spray-deposited onto a miniaturized three-electrode system on a glass substrate and activated using highly purified atomic oxygen generated in radiofrequency plasma; this introduced oxygen-containing functional groups into the SWCNT surface without fatal loss of the original physicochemical properties of the CNTs. The carboxylated SWCNT electrodes were then selectively modified via amidation or esterification for covalent immobilization of the biomacromolecules. The plasma-treated SWCNT-based sensing electrode had an approximately six times larger effective area than the untreated SWCNT-based electrode, which significantly amplified the amperometric electrochemical signal. Finally, the efficacy of plasma-functionalized SWCNT (pf-SWCNT) as a biointerface was examined by immobilizing glucose oxidase, Legionella pneumophila ( L. pneumophila)-specific antibodies, L. pneumophila-originated DNAs, and thrombin-specific aptamers on the pf-SWCNT-based three-electrode devices. The pf-SWCNT films were found to support direct covalent immobilization of the above-listed biomacromolecules on the films and to thereby overcome the many drawbacks typically associated with simple physisorption. Thus, pf-SWCNT sensing electrodes on which biomacromolecules were covalently immobilized were found to be chemically stable and have a long lifetime.
authors.affiliation: Department of Biomicrosystem Technology, Korea University, Anam-dong, Seoul, 136-701, Republic of Korea.
authors.forename: Joon Hyub
authors.initials: JH
authors.lastname: Kim
authors.forename: Joon-Hyung
authors.initials: JH
authors.lastname: Jin
authors.forename: Jun-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Park
authors.forename: Nam Ki
authors.initials: NK
authors.lastname: Min
mesh_terms: D000907:Antibodies, Bacterial / Q000737:chemistry / Q000276:immunology; D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation*; D015342:DNA Probes / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D007118:Immunoassay; D007875:Legionella; D046911:Macromolecular Substances / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D058626:Plasma Gases / Q000737:chemistry*; D011487:Protein Conformation; D013917:Thrombin / Q000378:metabolism
chemical_list: D000907:Antibodies, Bacterial; D052157:Aptamers, Nucleotide; D015342:DNA Probes; D004800:Enzymes, Immobilized; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D058626:Plasma Gases; D005949:Glucose Oxidase; D013917:Thrombin; D005947:Glucose; D010100:Oxygen