title: A highly sensitive, label-free gene sensor based on a single conducting polymer nanowire.
abstract: A prerequisite for exploiting sensing devices based on semiconductor nanowires is ultra-sensitive and selective direct electrical detection of biological and chemical species. Here, we constructed a transducer based on copolymer of poly(3,4,-ethylenedioxythiophene) (PEDOT) and carboxylic group functionalised PEDOT single nanowire in between gold electrodes, followed by covalent attachment of amino-modified probe oligonucleotide. The target ODNs specific to Homo sapiens Breast and ovarian cancer cells were detected at femtomolar concentration and incorporation of negative controls (non-complementary ODN) were clearly discriminated by the sensor. The ex situ measurements were performed by using two terminal device setup and the changes in the interface of the nanowire associated with the association or dissociation of ODNs were measured as change in resistance. In addition, in situ measurements were performed by utilizing scanning ion conductance microscopy to measure the change in resistance of probe modified nanowire upon addition of different concentration of target ODNs in presence of relevant buffer. The constructed, nano sensor showed highly sensitive concentration dependent resistance change.
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand.
authors.forename: Bhuvaneswari
authors.initials: B
authors.lastname: Kannan
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand. Electronic address: david.williams@auckland.ac.nz.
authors.forename: David E
authors.initials: DE
authors.lastname: Williams
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand.
authors.forename: Cosmin
authors.initials: C
authors.lastname: Laslau
authors.affiliation: Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand. Electronic address: j.travas-sejdic@auckland.ac.nz.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Travas-Sejdic
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D001943:Breast Neoplasms / Q000235:genetics; D019086:Bridged Bicyclo Compounds, Heterocyclic; D004273:DNA, Neoplasm / Q000032:analysis* / Q000235:genetics*; D005260:Female; D019398:Genes, BRCA1; D006801:Humans; D053770:Nanowires / Q000737:chemistry; D015345:Oligonucleotide Probes / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics; D011108:Polymers; D045663:Quantum Dots; D012680:Sensitivity and Specificity
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D004273:DNA, Neoplasm; D015345:Oligonucleotide Probes; D011108:Polymers; C121383:poly(3,4-ethylene dioxythiophene)