Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7230431 | Biosensors and Bioelectronics | 2016 | 8 Pages |
Abstract
We have presented an extensible, facile and sensitive multidimensional sensor based on DNA-gold nanoparticle (DNA-AuNP) conjugates for heavy metal ions (Ag+, Hg2+, Cr3+, Sn4+, Cd2+, Cu2+, Pb2+, Zn2+, and Mn2+) 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 50Â nM with 100% identification accuracy is obtained. Remarkably, Cu2+ and Hg2+ ions with similar catalytic performance at various concentrations (300Â nM, 400Â nM, 500Â nM, respectively) and the mixture of the two metal ions with different volume ratios (total metal ion concentration: 500Â nM) 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.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Lulu Tan, Zhengbo Chen, Yan Zhao, Xiangcong Wei, Yonghui Li, Chi Zhang, Xinling Wei, Xiaochen Hu,