title: DNA polymorphism sensitive impedimetric detection on gold-nanoislands modified electrodes.
abstract: Nanocomposite materials are being increasingly used in biosensing applications as they can significantly improve biosensor performance. Here we report the use of a novel impedimetric genosensor based on gold nanoparticles graphite-epoxy nanocomposite (nanoAu-GEC) for the detection of triple base mutation deletion in a cystic-fibrosis (CF) related human DNA sequence. The developed platform consists of chemisorbing gold nano-islands surrounded by rigid, non-chemisorbing, and conducting graphite-epoxy composite. The ratio of the gold nanoparticles in the composite was carefully optimized by electrochemical and microscopy studies. Such platform allows the very fast and stable thiol immobilization of DNA probes on the gold islands, thus minimizing the steric and electrostatic repulsion among the DNA probes and improving the detection of DNA polymorphism down to 2.25fmol by using electrochemical impedance spectroscopy. These findings are very important in order to develop new and renewable platforms to be used in point-of-care devices for the detection of biomolecules.
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 63737, Singapore. Electronic address: a.bonanni@ntu.edu.sg.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bonanni
authors.affiliation: Sensors and Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Pividori
authors.affiliation: Sensors and Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Barcelona, Spain. Electronic address: manel.delvalle@uab.cat.
authors.forename: Manel
authors.initials: M
authors.lastname: del Valle
mesh_terms: D015374:Biosensing Techniques; D015342:DNA Probes; D058266:Dielectric Spectroscopy; D004566:Electrodes; D004853:Epoxy Resins / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D015342:DNA Probes; D004853:Epoxy Resins; D009841:Oligonucleotides; D013438:Sulfhydryl Compounds; D006046:Gold; D006108:Graphite
keywords: Cyctic fibrosis; DNA polymorphism; Electrochemical impedance spectroscopy; Gold nanocomposite; Gold nanoparticles amplification