title: Magnetically trigged direct electrochemical detection of DNA hybridization using Au67 quantum dot as electrical tracer.
abstract: A novel gold nanoparticle-based protocol for detection of DNA hybridization based on a magnetically trigged direct electrochemical detection of gold quantum dot tracers is described. It relies on binding target DNA (here called DNA1) with Au(67) quantum dot in a ratio 1:1, followed by a genomagnetic hybridization assay between Au(67)-DNA1 and complementary probe DNA (here called DNA2) marked paramagnetic beads. Differential pulse voltammetry is used for a direct voltammetric detection of resulting Au(67) quantum dot-DNA1/DNA2-paramagnetic bead conjugate on magnetic graphite-epoxy composite electrode. The characterization, optimization, and advantages of the direct electrochemical detection assay for target DNA are demonstrated. The two main highlights of presented assay are (1) the direct voltammetric detection of metal quantum dots obviates their chemical dissolution and (2) the Au(67) quantum dot-DNA1/DNA2-paramagnetic bead conjugate does not create the interconnected three-dimensional network of Au-DNA duplex-paramagnetic beads as previously developed nanoparticle DNA assays, pushing down the achievable detection limits.
authors.affiliation: Grup de Sensors i Biosensors, Departament de Química, Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia, Spain.
authors.forename: Martin
authors.initials: M
authors.lastname: Pumera
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Castañeda
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Pividori
authors.forename: Ramon
authors.initials: R
authors.lastname: Eritja
authors.forename: Arben
authors.initials: A
authors.lastname: Merkoçi
authors.forename: Salvador
authors.initials: S
authors.lastname: Alegret
mesh_terms: D004247:DNA / Q000235:genetics*; D004563:Electrochemistry / Q000379:methods; D006046:Gold; D008280:Magnetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D011199:Potentiometry; D011789:Quantum Theory
chemical_list: D006046:Gold; D004247:DNA