title: DNA-based chemiluminescent nanoprobes for highly sensitive and selective detection of mercury(II) ion.
abstract: A simple and sensitive DNA-stablized gold nanoparticle (AuNP)-based chemiluminescent (CL) probe for detecting mercury ion (Hg(2+)) in aqueous solution has been developed. The CL strategy relies upon the catalytic activity of unmodified AuNPs on the luminol-H2 O2 CL reaction, and the interaction of unmodified AuNPs with DNA. The unmodified AuNPs can effectively differentiate unstructured and folded DNA. The DNA desorbs from AuNPs in the presence of Hg(2+), leading to the increase in CL signal. By rationally varying the number of thymine in single-strand oligonucleotides, the detection range could be tuned. Employing single-strand oligonucleotides with 14 thymine in the detecting system, a sensitive linear range for Hg(2+) ions from 5.0 × 10(-10) to 1.0 × 10(-7) mol/L and a detection limit of 2.1 × 10(-10) mol/L are obtained. Changing the number of thymine to 10 and 6, it leads to a narrow detection range but a high sensitivity. Besides, DNA-based CL nanoprobes exhibit a remarkable selectivity for Hg(2+) ions over a variety of competing metal ions.
authors.affiliation: Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, People's Republic of China.
authors.forename: Xijuan
authors.initials: X
authors.lastname: Yu
authors.forename: Xiangnan
authors.initials: X
authors.lastname: Liu
authors.forename: Chuanqin
authors.initials: C
authors.lastname: Mou
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Wang
mesh_terms: D002413:Cations, Divalent / Q000032:analysis / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D015335:Molecular Probes / Q000032:analysis / Q000737:chemistry
chemical_list: D002413:Cations, Divalent; D015335:Molecular Probes; D006046:Gold; D004247:DNA; D008628:Mercury
keywords: DNA; chemiluminescence; gold nanoparticles; mercury (II) ion; tunable detection range