title: Method for detection of Hg2+ based on the specific thymine-Hg2+-thymine interaction in the DNA hybridization on the surface of quartz crystal microbalance.
abstract: A simple and sensitive method was developed for the detection of mercury ions with quartz crystal microbalance (QCM), based on the specific thymine-Hg(2+)-thymine (T-Hg(2+)-T) interaction and gold nanoparticle-mediated signal amplification. To enhance the sensitivity of detection a sandwich hybridization approach was adopted in this work. The QCM gold surface was modified with the probe SH-oligonucleotides (Oligo-1) and 6-Mercapto-1-hexanol to form an active surface for the hybridization of a longer ss-DNA (Oligo-2), and then Oligo-3 hybridazated with an excess and matching part of Oligo-2. In all oligonucleotides, there existed T bases. In the presence of Hg(2+) ions, special T-Hg(2+)-T reaction greatly enhanced the hybridization of oligonucleotides and detection sensitivity. The gold nanoparticle (Au NPs) amplifier method further increased the sensitivity of detection. A detection sensitivity of 5nM Hg(2+) was obtained in the QCM system, whereas other coexisting metal ions (such as Ni(2+), Mg(2+), Co(2+), Cr(3+), Pb(2+), Cd(2+), Mn(2+), Ba(2+)) had no significant interference. This method reveals a new approach for the manufacture of a kind of simple and low cost sensors for the Hg(2+) detection.
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Colloid and Interface Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhonghan
authors.initials: Z
authors.lastname: Sheng
authors.forename: Jianhua
authors.initials: J
authors.lastname: Han
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.forename: Long
authors.initials: L
authors.lastname: Jiang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004785:Environmental Pollutants / Q000032:analysis*; D006046:Gold / Q000737:chemistry* / Q000378:metabolism; D000441:Hexanols / Q000737:chemistry; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D015345:Oligonucleotide Probes / Q000737:chemistry / Q000378:metabolism*; D010316:Particle Size; D058525:Quartz Crystal Microbalance Techniques; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties; D013941:Thymine / Q000737:chemistry / Q000378:metabolism*
chemical_list: C503488:6-mercapto-1-hexanol; D004785:Environmental Pollutants; D000441:Hexanols; D015345:Oligonucleotide Probes; D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA; D008628:Mercury; D013941:Thymine