title: Detection and Quantitation of Heavy Metal Ions on Bona Fide DVDs Using DNA Molecular Beacon Probes.
abstract: A sensitive and cost-effective method for the simultaneous quantitation of trace amounts of Hg(2+) and Pb(2+) in real-world samples has been developed using DNA molecular beacon probes bound to bona fide digital video discs (DVDs). With specially designed T-rich or G-rich loop sequences, the detection is based on the strong T-Hg(2+)-T coordination chemistry of Hg(2+) and the formation of G-quadruplexes induced by Pb(2+), respectively. In particular, the presence of metal cations leads to hairpin opening and exposure of the terminal biotin moiety for binding nanogold-streptavidin conjugates. The recognition signal was subsequently enhanced by gold nanoparticle-promoted silver deposition, which leads to quantifiable digital signals upon reading with a standard computer drive. This method exhibits a wide response range and low detection limits for both Hg(2+) and Pb(2+). In addition, the quantitative determination of heavy metals in food products (e.g., rice samples) has been demonstrated and the method compares favorably with other optical sensors developed recently.
authors.affiliation: †Key Laboratory of Advanced Transducers and Intelligent Control Systems (Ministry of Education and Shanxi Province), College of Physics and Optoelectronic Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China.|§Department of Chemistry, Beijing Normal University, Beijing 100875, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: ‡Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Jessica X H
authors.initials: JX
authors.lastname: Wong
authors.affiliation: †Key Laboratory of Advanced Transducers and Intelligent Control Systems (Ministry of Education and Shanxi Province), College of Physics and Optoelectronic Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Li
authors.affiliation: §Department of Chemistry, Beijing Normal University, Beijing 100875, China.
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Li
authors.affiliation: †Key Laboratory of Advanced Transducers and Intelligent Control Systems (Ministry of Education and Shanxi Province), College of Physics and Optoelectronic Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China.|‡Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Hua-Zhong
authors.initials: HZ
authors.lastname: Yu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D016250:Compact Disks; D015342:DNA Probes / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis*; D055029:Inverted Repeat Sequences; D007854:Lead / Q000032:analysis*; D008628:Mercury / Q000032:analysis*
chemical_list: D015342:DNA Probes; D004785:Environmental Pollutants; D007854:Lead; D008628:Mercury