title: Multiplex electrical detection of avian influenza and human immunodeficiency virus with an underlap-embedded silicon nanowire field-effect transistor.
abstract: The label-free electrical detection of the binding of antibodies and antigens of avian influenza (AI) and human immunodeficiency (HIV) viruses is demonstrated through an underlap-embedded silicon (Si) nanowire field-effect transistor. The proposed sensor was fabricated on a silicon bulk wafer by a top-down process. Specifically, a Si nanowire was fabricated by a combined isotropic and anisotropic patterning technique, which is one route plasma etching process. The sensor was fabricated by a self-aligned process to the gate with tilted implantation, and it allows precise control of the underlap region. This was problematic in earlier underlap field-effect transistors fabricated by a conventional gate-last process. As a sensing metric to detect the binding of a targeted antibody, the transfer characteristic change was traced. Before and after differences between the antibody binding results were caused by changes in the channel potential on the underlap region due to the charge effect arising from the biomolecules; this is also supported by a simulation. Furthermore, the multiplex detection of AI and HIV is demonstrated, showing distinctive selectivity in each case. Thus, the proposed device has inherent benefits for the label-free, electrical, and multiplex detection of biomolecules. Moreover, its processes are compatible with commercialized technology presently used to fabricate semiconductor devices. This advantage is attractive for those involved in the construction of a point-of-care testing (POCT) system on a chip involving simple, low-cost and low-risk fabrication processes of novel structures and materials.
authors.affiliation: Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jee-Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Dong-Il
authors.initials: DI
authors.lastname: Moon
authors.affiliation: Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
authors.forename: Tae Jung
authors.initials: TJ
authors.lastname: Park
authors.affiliation: Department of Chemical & Biomolecular Engineering, Department of Biological Sciences, Department of Bio & Brain Engineering, Bioinformatics Research Center, Center for Systems & Synthetic Biotechnology, and Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea. Electronic address: ykchoi@ee.kaist.ac.kr.
authors.forename: Yang-Kyu
authors.initials: YK
authors.lastname: Choi
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis / Q000276:immunology; D000956:Antigens, Viral / Q000032:analysis / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation*; D001717:Birds; D045424:Complex Mixtures / Q000032:analysis; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006678:HIV / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D009980:Influenza A virus / Q000276:immunology / Q000302:isolation & purification*; D053770:Nanowires / Q000737:chemistry / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry; D014173:Transistors, Electronic
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D045424:Complex Mixtures; D012825:Silicon
keywords: Avian influenza; Electrical biosensor; Field-effect transistor; Human immunodeficiency virus; Label-free detection; Underlap field-effect transistor