title: Toehold-mediated DNA displacement-based surface-enhanced Raman scattering DNA sensor utilizing an Au-Ag bimetallic nanodendrite substrate.
abstract: A simple and sensitive surface enhanced Raman scattering (SERS)-based DNA sensor that utilizes the toehold-mediated DNA displacement reaction as a target-capturing scheme has been demonstrated. For a SERS substrate, Au-Ag bimetallic nanodendrites were electrochemically synthesized and used as a sensor platform. The incorporation of both Ag and Au was employed to simultaneously secure high sensitivity and stability of the substrate. An optimal composition of Ag and Au that satisfied these needs was determined. A double-strand composed of 'a probe DNA (pDNA)' complementary to 'a target DNA (tDNA)' and 'an indicator DNA tagged with a Raman reporter (iDNA)' was conjugated on the substrate. The conjugation made the reporter molecule close to the surface and induced generation of the Raman signal. The tDNA released the pre-hybridized iDNA from the pDNA via toehold-mediated displacement, and the displacement of the iDNA resulted in the decrease of Raman intensity. The variation of percent intensity change was sensitive and linear in the concentration range from 200fM to 20nM, and the achieved limit of detection (LOD) was 96.3fM, superior to those reported in previous studies that adopted different signal taggings based on such as fluorescence and electrochemistry.
authors.affiliation: Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea.
authors.forename: Saetbyeol
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea.
authors.forename: Huan
authors.initials: H
authors.lastname: Tran Ngoc
authors.affiliation: Department of Chemistry, Research Institute for Basic Sciences, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors.forename: Joohoon
authors.initials: J
authors.lastname: Kim
authors.affiliation: BIO-IT Foundry Technology Institute, Pusan National University, Busan 609-735, Republic of Korea; Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 626-770, Republic of Korea. Electronic address: yoosy@pusan.ac.kr.
authors.forename: So Young
authors.initials: SY
authors.lastname: Yoo
authors.affiliation: Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea. Electronic address: hoeil@hanyang.ac.kr.
authors.forename: Hoeil
authors.initials: H
authors.lastname: Chung
mesh_terms: D004247:DNA / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D012834:Silver; D006046:Gold; D004247:DNA
keywords: Bimetallic nanodendrite; Signal-off sensor; Surface-enhanced Raman scattering DNA sensor; Toehold-mediated DNA strand displacement reaction