Magnetically trigged direct electrochemical detection of DNA hybridization using Au67 quantum dot as electrical tracer

Martin Pumera, Maria Teresa Castañeda, Maria Isabel Pividori, Ramon Eritja, Arben Merkoç, Salvador Alegret

Research output: Contribution to journalArticlepeer-review

124 Citations (Scopus)


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 Au67 quantum dot in a ratio 1:1, followed by a genomagnetic hybridization assay between Au67-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 Au67 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.

Original languageEnglish
Pages (from-to)9625-9629
Number of pages5
Issue number21
Publication statusPublished - 2005 Oct 11

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry


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