title: Single wall carbon nanotube electrode system capable of quantitative detection of CD4+T cells.
abstract: Development of CNT-based CD4+T cell imunosensors remains in its infancy due to the poor immobilization efficiency, lack of reproducibility, and difficulty in providing linear quantification. Here, we developed a fully-integrated single wall carbon nanotube (SWCNT)-based immunosensor capable of selective capture and linear quantification of CD4+T cells with greater dynamic range. By employing repeated two-step oxygen (O2) plasma treatment processes with 35 days of recovery periods, we achieved the enhanced functionalization of the CNT surface and the removal of the byproduct of spray-coated SWCNTs that hinders charge transfer and stable CD4+T cell sensing. As a result, a linear electrochemical signal was generated in direct proportion to the bound cells. The slope of a SWCNT electrode in a target concentration range (102~106cells/mL) was 4.55×10-2μA per concentration decade, with the lowest detection limit of 1×102cells/mL. Since the reduced number of CD4+T cell counts in patients' peripheral blood corresponds to the progression of HIV disease, our CD4+T cell-immunosensor provides a simple and low-cost platform which can fulfill the requirement for the development of point-of-care (POC) diagnostic technologies for human immunodeficiency virus (HIV) patients in resource-limited countries.
authors.affiliation: Department of Electro-Mechanical Systems Engineering, Korea University, Sejong, Chungnam 30019, Republic of Korea.
authors.forename: Joonhyub
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Biomicrosystem Technology, Korea University, Seoul 136-701, Republic of Korea; Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-713, Republic of Korea.
authors.forename: Gayoung
authors.initials: G
authors.lastname: Park
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-713, Republic of Korea.
authors.forename: Seoho
authors.initials: S
authors.lastname: Lee
authors.affiliation: KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701, Republic of Korea.
authors.forename: Suk-Won
authors.initials: SW
authors.lastname: Hwang
authors.affiliation: Department of Electro-Mechanical Systems Engineering, Korea University, Sejong, Chungnam 30019, Republic of Korea. Electronic address: nkmin@korea.ac.kr.
authors.forename: Namki
authors.initials: N
authors.lastname: Min
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-713, Republic of Korea; Department of Melanoma Medical Oncology and Immunology, MD Anderson Cancer Center, Houston, Texas 77054, United States. Electronic address: kyunglee@korea.ac.kr.
authors.forename: Kyung-Mi
authors.initials: KM
authors.lastname: Lee
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D002469:Cell Separation / Q000295:instrumentation; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D018655:Lymphocyte Count / Q000295:instrumentation*; D008810:Mice, Inbred C57BL; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010100:Oxygen / Q000737:chemistry; D058626:Plasma Gases / Q000737:chemistry; D019095:Point-of-Care Systems
chemical_list: D055910:Antibodies, Immobilized; D037742:Nanotubes, Carbon; D058626:Plasma Gases; D010100:Oxygen
keywords: CD4(+) T cells; Electrochemical analysis; O(2) plasma treatment; SWCNT; T cell immunosensor