title: Cu@Au alloy nanoparticle as oligonucleotides labels for electrochemical stripping detection of DNA hybridization.
abstract: Synthesis of the novel Cu@Au alloy nanoparticle and its application in an electrochemical DNA hybridization detection assay is described in this article. We report a low-temperature method for generating core-shell particles consisting of a core of Cu and a thin layer of Au shell that can be readily functionalized with oligonucleotides. Core-shell Cu@Au particles were successfully labeled to a 5'-alkanethiol capped oligonucleotides probe that is related to the colitoxin gene. The DNA genetic sensing assay relies on the electrostatic adsorption of target oligonucleotides onto conducting polypyrrole (PPy) surface at the glassy carbon electrode (GCE), and its hybridization to the alloy particle-oligonucleotides DNA probe. Hybridization events between probe and target were monitored by the release of the copper metal atoms anchored on the hybrids by oxidative metal dissolution and the indirectly determination of the solubilized Cu2+ ions by sensitive anodic stripping voltammetry (ASV). The detection limit is 5.0 pmol l(-1) of target oligonucleotides. The Cu@Au core-shell nanoparticles combining the surface modification properties of Au with the good electrochemical activity of Cu core shows their perspective application in the electrochemical DNA hybridization analysis assay.
authors.affiliation: Department of Chemistry, East China Normal University, Shanghai 200062, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Cai
authors.forename: Ningning
authors.initials: N
authors.lastname: Zhu
authors.forename: Ying
authors.initials: Y
authors.lastname: Jiang
authors.forename: Pingang
authors.initials: P
authors.lastname: He
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Fang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D015342:DNA Probes / Q000138:chemical synthesis / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D006047:Gold Alloys / Q000138:chemical synthesis / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D009841:Oligonucleotides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods; D013194:Staining and Labeling / Q000379:methods
chemical_list: D020099:Coated Materials, Biocompatible; D015342:DNA Probes; D006047:Gold Alloys; D009841:Oligonucleotides; D003300:Copper; D004247:DNA