title: Detection of IFN-γ for latent tuberculosis diagnosis using an anodized aluminum oxide-based capacitive sensor.
abstract: We describe a rapid, sensitive, and label-free method to detect interferon-gamma (IFN-γ), a biomarker of latent tuberculosis infection (LTBI). IFN-γ is detected by measuring the capacitance change caused by its binding to an anti-IFN-γ antibody. The antibody is immobilized on the surface of an anodized aluminum oxide (AAO)-based capacitive sensor. With this technique, IFN-γ can be detected in the range of ~0.1 pg/ml to ~10 ng/ml, with a detection limit of 0.2 pg/ml. We have also measured the concentration of IFN-γ in clinical samples using the AAO-based capacitive sensor and compared this concentration with the results of the commercial QuantiFERON-TB Gold (QFT-G) ELISA kit to determine whether the two sets of data are consistent. Comparable results were obtained with the two measurement strategies, demonstrating the applicability of the AAO-based capacitive sensor to the diagnosis of LTBI.
authors.affiliation: Department of Physics, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Joo Hyoung
authors.initials: JH
authors.lastname: Kim
authors.forename: Young Wook
authors.initials: YW
authors.lastname: Chang
authors.forename: Eun
authors.initials: E
authors.lastname: Bok
authors.forename: Hyun-Jeong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hyejon
authors.initials: H
authors.lastname: Lee
authors.forename: Sang-Nae
authors.initials: SN
authors.lastname: Cho
authors.forename: Jeon-Soo
authors.initials: JS
authors.lastname: Shin
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Yoo
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D025802:Electric Capacitance; D004566:Electrodes; D004867:Equipment Design; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D007371:Interferon-gamma / Q000097:blood*; D055985:Latent Tuberculosis / Q000097:blood / Q000175:diagnosis*
chemical_list: D055910:Antibodies, Immobilized; D007371:Interferon-gamma; D000537:Aluminum Oxide
keywords: Anodized aluminum oxide; Capacitive sensor; IFN-γ; Latent tuberculosis infection