title: Plasmonic SERS biosensing nanochips for DNA detection.
abstract: The development of rapid, cost-effective DNA detection methods for molecular diagnostics at the point-of-care (POC) has been receiving increasing interest. This article reviews several DNA detection techniques based on plasmonic-active nanochip platforms developed in our laboratory over the last 5 years, including the molecular sentinel-on-chip (MSC), the multiplex MSC, and the inverse molecular sentinel-on-chip (iMS-on-Chip). DNA probes were used as the recognition elements, and surface-enhanced Raman scattering (SERS) was used as the signal detection method. Sensing mechanisms were based on hybridization of target sequences and DNA probes, resulting in a distance change between SERS reporters and the nanochip's plasmonic-active surface. As the field intensity of the surface plasmon decays exponentially as a function of distance, the distance change in turn affects SERS signal intensity, thus indicating the presence and capture of the target sequences. Our techniques were single-step DNA detection techniques. Target sequences were detected by simple delivery of sample solutions onto DNA probe-functionalized nanochips and measuring the SERS signal after appropriate incubation times. Target sequence labeling or washing to remove unreacted components was not required, making the techniques simple, easy-to-use, and cost-effective. The usefulness of the nanochip platform-based techniques for medical diagnostics was illustrated by the detection of host genetic biomarkers for respiratory viral infection and of the dengue virus gene.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.|Fitzpatrick Institute for Photonics, Duke University, Durham, NC, 27708, USA.
authors.forename: Hoan T
authors.initials: HT
authors.lastname: Ngo
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.|Fitzpatrick Institute for Photonics, Duke University, Durham, NC, 27708, USA.
authors.forename: Hsin-Neng
authors.initials: HN
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.|Fitzpatrick Institute for Photonics, Duke University, Durham, NC, 27708, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Fales
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA. tuan.vodinh@duke.edu.|Fitzpatrick Institute for Photonics, Duke University, Durham, NC, 27708, USA. tuan.vodinh@duke.edu.|Department of Chemistry, Duke University, Durham, NC, 27708, USA. tuan.vodinh@duke.edu.
authors.forename: Tuan
authors.initials: T
authors.lastname: Vo-Dinh
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation / Q000379:methods; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry; D004867:Equipment Design; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis / Q000191:economics / Q000295:instrumentation / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*
chemical_list: D015342:DNA Probes; D004247:DNA
keywords: DNA biosensor; DNA detection; Molecular sentinel-on-chip; Multiplex DNA detection; Surface-enhanced Raman scattering