title: Carbon nanotube-assisted enhancement of surface plasmon resonance signal.
abstract: We describe a method of amplifying the biosensing signal in surface plasmon resonance (SPR)-based immunoassays using an antibody-carbon nanotube (CNT) conjugate. As a model system, human erythropoietin (EPO) and human granulocyte macrophage colony-stimulating factor (GM-CSF) were detected by sandwich-type immunoassays using an SPR biosensor. For the amplification of the SPR signal, the CNT was conjugated with a polyclonal antibody, and then the conjugates were reacted with antibodies coupled with the target proteins. This amplification strategy increases the dynamic range of the immunoassays and enhances the detection sensitivity. The SPR immunoassays, combined with the CNT-assisted signal amplification method, provided a wide dynamic range over four orders of magnitude for both EPO and GM-CSF (0.1-1,000 ng/ml). The CNT amplification method is expected to realize the detection of picogram levels and a wide dynamic detection range of multiple proteins, enabling it to offer a robust analysis tool for the development of biopharmaceutical production.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology, Yuseong, Daejeon 305-600, Republic of Korea.
authors.forename: Eun Gyo
authors.initials: EG
authors.lastname: Lee
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Park
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Jeong
authors.forename: Seung Hui
authors.initials: SH
authors.lastname: Lee
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Baek
authors.forename: Hong Weon
authors.initials: HW
authors.lastname: Lee
authors.forename: Joon Ki
authors.initials: JK
authors.lastname: Jung
authors.forename: Bong Hyun
authors.initials: BH
authors.lastname: Chung
mesh_terms: D000906:Antibodies / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods; D004921:Erythropoietin / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D000906:Antibodies; D037742:Nanotubes, Carbon; D011994:Recombinant Proteins; D004921:Erythropoietin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor