Title: Studies towards a switch-off optical DNA sensor based on poly(p-phenylenevinylene) grafted magnetic beads

Authors: Anupama R. Gulur Srinivas; David Barker; Jadranka Travas-Sejdic

Addresses: Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand ' Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand ' 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

Abstract: Much effort has been devoted towards developing efficient DNA sensors for applications in medical diagnostics, food contamination, forensics, biodefence and environmental monitoring. In this study we further evaluate the selectivity of our recently developed switch-off sensor design that utilises sandwich hybridisation between a photoluminescent anionic conjugated polymer (CP) bound capture probe coated onto magnetic beads, target and the dye labelled signalling probe. The hybridisation-readout in our sensor was monitored by superquenching (switch-off) of the fluorescence of CP by Cy3 dye. We have used two recently synthesised carboxylic functionalised poly(p-phenylene vinylenes) (PPVs), poly-6,6′-((2-((E)-2,5-dimethoxy-4-((E)-prop-1-en-1-yl)styryl)-5-methyl-1,4 phenylene)bis(oxy))dihexanoic acid (PDDMe) and mono glycol units poly(6,6′-((2-((E)-2,5-bis(2-methoxyethoxy)-4-((E)-prop-1-en-1-yl)styryl)-5-methyl-1,4-phenylene)bis(oxy))dihexanoic acid) (PDMonoG) to test as part of this sensing design with complementary, non-complementary and mis-matched DNA. PDMonoG demonstrated better selectivity and holds promise towards development of robust platforms for commercial DNA sensors.

Keywords: conjugated polymers; PPV; poly(p-phenylene vinylenes); Cy3 dyes; superquenching; switch-off sensor design; optical sensors; DNA sensors; magnetic beads; sandwich hybridisation; photoluminescence; nanotechnology.

DOI: 10.1504/IJNT.2014.060587

International Journal of Nanotechnology, 2014 Vol.11 No.5/6/7/8, pp.645 - 659

Published online: 20 Apr 2014 *

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