title: Quantum dot-based immunoassay enhanced by high-density vertical ZnO nanowire array.
abstract: In this paper, we report an efficient and high-performance immunoassay platform by combining high-density vertical ZnO nanowire array with photostable quantum dot (QD) labeling. The ZnO nanowire array provides a large surface area for the immobilization of biomolecules, which makes it an efficient substrate for the immunoreaction of biomolecules. When a sandwich immunoassay with QD label was conducted on various substrates, the ZnO nanowire substrate showed stronger fluorescence signal than ZnO thin film and bare glass substrates by 3.8 and 8.5 times, respectively. We found that the fluorescence resonance energy transfer (FRET) from QD to ZnO nanowire could be suppressed by extending their distance with multilayer biotin-streptavidin complex. In addition, we demonstrated the QD-based immunoassay of carcinoembryonic antigen (CEA) on a ZnO nanowire substrate, showing an excellent immunoassay performance with a very low detection limit (0.001 ng/mL) and a large detection range up to 100 ng/mL.
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jung
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Seyong
authors.initials: S
authors.lastname: Kwon
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea; KAIST Institute for the NanoCentury, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea. Electronic address: jekyun@kaist.ac.kr.
authors.forename: Je-Kyun
authors.initials: JK
authors.lastname: Park
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea; KAIST Institute for the NanoCentury, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea. Electronic address: inkyu@kaist.ac.kr.
authors.forename: Inkyu
authors.initials: I
authors.lastname: Park
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation*; D007118:Immunoassay / Q000295:instrumentation*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D002272:Carcinoembryonic Antigen; D015034:Zinc Oxide
keywords: Biosensing; Carcinoembryonic antigen; Fluorescence resonance energy transfer; Immunoassay; Quantum dot; ZnO nanowire array