Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7232632 | Biosensors and Bioelectronics | 2015 | 20 Pages |
Abstract
In this study, plasmonic heteropyramids (HPs) made from two different sized gold nanoparticles (Au NPs) and five ssDNA sequences and their application for ultrasensitive detection of mercury ion (Hg2+) were demonstrated. Four ssDNA sequences were used as building blocks to form a pyramidal DNA frame, which contains a T-rich probe DNA at one vertex and three sulfhydryl groups modified with 10 nm Au NPs at the other three vertices. Another T-rich DNA sequence was modified and attached to a 25nm Au NP. In the presence of Hg2+ ions, 25 nm Au NPs hybridized with pyramidal DNA frame to build the plasmonic HPs based on T-Hg2+-T interaction, which exhibits unprecedented circular dichroism (CD) signal in the visible region. Based on this mechanism, a simple, high sensitive and selective chiroplasmonic HPs-based probe was constructed and demonstrated for Hg2+ ions detection. Under optimized conditions, Hg2+ ions could be selectively detected in a concentration range from 1 to 500 pg mLâ1 with a limit of detection of 0.2 pg mLâ1, which is much lower than the strictest Hg2+ safety requirement of 1 ng mLâ1 in water.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Wenjing Yan, Yongli Wang, Hong Zhuang, Jianhao Zhang,