title: Switch on or switch off: an optical DNA sensor based on poly(p-phenylenevinylene) grafted magnetic beads.
abstract: There has been an enormous demand for commercial label-free DNA sensors in a diverse range of fields including pre-emptive medicine, diagnostics, environmental monitoring, and food industry. Addressing the need for sensitive, selective and facile DNA sensors, we demonstrate a novel switch on/off sensor design that utilizes sandwich hybridization between photoluminescent anionic conjugated polyelectrolyte (CPE) bound captureprobe coated onto magnetic beads, target and the signaling probe. The hybridization-readout in our sensor was monitored by either fluorescence resonance energy transfer (FRET, switch-on) or superquenching (switch-off) depending on the type of signaling probe used. Moreover recent designs that utilize beads for sensing DNA have been limited towards using electrostatic interactions or intercalation of dyes to observe FRET. To our knowledge this is the first report of a switch on/off sensor utilizing either FRET or superquenching thus providing flexibility for future development of such rapid, facile and sensitive DNA sensors. The FRET-based sensor was investigated by optimizing the reaction parameters and selectivity. A low detection limit of 240 fmol in 2 mL of SSC buffer was achieved.
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Anupama R Gulur
authors.initials: ARG
authors.lastname: Srinivas
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Key Laboratory of Polarized Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200062, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: David
authors.initials: D
authors.lastname: Barker
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand. Electronic address: j.travas-sejdic@auckland.ac.nz.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Travas-Sejdic
mesh_terms: D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D004247:DNA / Q000032:analysis*; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D008280:Magnetics; D015345:Oligonucleotide Probes; D055620:Optical Phenomena; D011145:Polyvinyls
chemical_list: D015345:Oligonucleotide Probes; D011145:Polyvinyls; C470024:poly(4-phenylenevinylene); D004247:DNA