title: Dual channel sensor for detection and discrimination of heavy metal ions based on colorimetric and fluorescence response of the AuNPs-DNA conjugates.
abstract: We have presented an extensible, facile and sensitive multidimensional sensor based on DNA-gold nanoparticle (DNA-AuNP) conjugates for heavy metal ions (Ag(+), Hg(2+), Cr(3+), Sn(4+), Cd(2+), Cu(2+), Pb(2+), Zn(2+), and Mn(2+)) discrimination. In the presence of metal ions, the excluded effect of DNA and AuNPs with the same negative charges is disrupted, and the amount of FAM-labeled DNA adsorbed on AuNP surfaces increases, resulting in a more obvious fluorescence quenching effect. With the addition of NH2OH and HAuCl4, AuNPs grow into morphologically varied nanostructures (spherical to branched) depending on the resulting aptamer coverage, which gives rise to different colored solutions (reddish blush, purple and blue) observed by naked eyes. By simply changing the DNA sequences, three sensing elements can be easily obtained and added into this dual-channel multidimensional sensor. 9 heavy metal ions are distinguished by linear discriminant analysis (LDA) and primary component analysis (PCA). A highly sensitive discrimination of metal ion targets with the detection limit as low as 50nM with 100% identification accuracy is obtained. Remarkably, Cu(2+) and Hg(2+) ions with similar catalytic performance at various concentrations (300nM, 400nM, 500nM, respectively) and the mixture of the two metal ions with different volume ratios (total metal ion concentration: 500nM) can be successfully discriminated. In addition, nine heavy metal ions are also well-distinguished in river samples, and the accuracy of discrimination of these metal ions samples reaches 100%. Therefore, it will broaden the application field of DNA-AuNP conjugates-based multidimensional sensors.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China; College of Resources Environment and Tourism, Capital Normal University, Beijing 100048, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China. Electronic address: czb979216@sina.com.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Xiangcong
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Hematology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Xinling
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Hu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D019216:Metals, Heavy / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004247:DNA; D006046:Gold; D019216:Metals, Heavy; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Discrimination; Dual channel; Gold nanoparticles; Heavy metal ions; Multidimensional