| 论文标题 |
Colorimetric determination of Hg(II) by combining the etching and aggregation effect of cysteine-modified Au-Ag core-shell nanorods |
| 作者 |
Jian Zhu *, Bing-zheng Zhao, Ying Qi, Jian-Jun Li, Xin Li, Jun-Wu Zhao* |
| 发表/完成日期 |
2017-11-01 |
| 期刊名称 |
Sensors & Actuators: B. Chemical |
| 期卷 |
255 |
| 相关文章 |
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| 论文简介 |
In this report, a simple and effective approach for colorimetric detection of Hg2+based on surface etchingand aggregation effect of cysteine-modified Au-Ag core-shell nanorods has been investigated. When theaddition of Hg2+has a low concentration under 60 M, electrostatic interaction-induced intense aggrega-tion of colloidal Au-Ag core-shell nanorods takes place. Thus the longitudinal plasmonic absorption peakdecreases rapidly, which also leads to the colloidal color become shallow. Whereas when the addition ofHg2+has a high concentration greater than 60 M, the adherent cysteine molecules break away from thesurface of nanorods due to the intense Hg-S bond. Then the bare nanorods have been etched under theaction of Hg2+. The decrease of the Ag shell results in the red shift of the longitudinal absorption peak,which further leads to the color change of the colloids. The sensing based on particle aggregation-inducedabsorption decrease has a linear response for Hg2+from 1 to 60 M with a theoretical detection limit of0.273 M. The sensing based on etching effect-induced red shift has a logarithmic response for Hg2+from60 to 250 M with a theoretical detection limit of 1.065 M. Interference test and real samples detec-tion results show that Hg2+could be specifically detected by using this probe based on Au-Ag core-shellnanorods.© 2017 Elsevier B.V. All rights reserved. |
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