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Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars

Reliable and sensitive methods to monitor mercury levels in real samples are highly important for environment protection and human health. Herein, a label-free colorimetric sensor for Hg(2+) quantitation using gold nanostar (GNS) has been demonstrated, based on the formation of Au-Hg amalgamate that...

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Autores principales: Xu, Dong, Yu, Shufang, Yin, Yueqin, Wang, Suyan, Lin, Qinlu, Yuan, Zhiqin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6277514/
https://www.ncbi.nlm.nih.gov/pubmed/30538981
http://dx.doi.org/10.3389/fchem.2018.00566
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author Xu, Dong
Yu, Shufang
Yin, Yueqin
Wang, Suyan
Lin, Qinlu
Yuan, Zhiqin
author_facet Xu, Dong
Yu, Shufang
Yin, Yueqin
Wang, Suyan
Lin, Qinlu
Yuan, Zhiqin
author_sort Xu, Dong
collection PubMed
description Reliable and sensitive methods to monitor mercury levels in real samples are highly important for environment protection and human health. Herein, a label-free colorimetric sensor for Hg(2+) quantitation using gold nanostar (GNS) has been demonstrated, based on the formation of Au-Hg amalgamate that leads to shape-evolution of the GNS and changes in its absorbance. Addition of ascorbic acid (AA) to GNS solution is important for quantitation of Hg(2+), mainly because it can reduce Hg(2+) to Hg to enhance amalgamation on the GNSs and stabilize GNSs. In addition to transmission electron microscopy images, the distribution of circular ratios of GNSs in the presence of 2 mM AA and various concentrations of Hg(2+) are used to show the morphology changes of the GNSs. Upon increasing the concentration of Hg(2+), the average circular ratio of GNSs decreases, proving GNS is approaching to sphere. The morphology change alters the longitudinal localized surface plasmonic resonance (LSPR) absorbance of the GNSs significantly. Under the optimum conditions, our sensor exhibits a dynamic response for Hg(2+) in the range of 1–4,000 nM with a detection limit of 0.24 nM. Upon Increasing Hg(2+) concentration, the solution color changes from greenish-blue, purple to red, which can be distinguished by the naked eye when the Hg(2+) concentration is higher than 250 nM. Owing to having a high surface-to-volume ratio and affinity toward Hg(0), the GNS is sensitive and selective (at least 50-fold over tested metal ions like Pb(2+)) toward Hg(2+) in the presence of AA. Practicality of this assay has been validated by the analysis of water samples without conducting tedious sample pretreatment.
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spelling pubmed-62775142018-12-11 Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars Xu, Dong Yu, Shufang Yin, Yueqin Wang, Suyan Lin, Qinlu Yuan, Zhiqin Front Chem Chemistry Reliable and sensitive methods to monitor mercury levels in real samples are highly important for environment protection and human health. Herein, a label-free colorimetric sensor for Hg(2+) quantitation using gold nanostar (GNS) has been demonstrated, based on the formation of Au-Hg amalgamate that leads to shape-evolution of the GNS and changes in its absorbance. Addition of ascorbic acid (AA) to GNS solution is important for quantitation of Hg(2+), mainly because it can reduce Hg(2+) to Hg to enhance amalgamation on the GNSs and stabilize GNSs. In addition to transmission electron microscopy images, the distribution of circular ratios of GNSs in the presence of 2 mM AA and various concentrations of Hg(2+) are used to show the morphology changes of the GNSs. Upon increasing the concentration of Hg(2+), the average circular ratio of GNSs decreases, proving GNS is approaching to sphere. The morphology change alters the longitudinal localized surface plasmonic resonance (LSPR) absorbance of the GNSs significantly. Under the optimum conditions, our sensor exhibits a dynamic response for Hg(2+) in the range of 1–4,000 nM with a detection limit of 0.24 nM. Upon Increasing Hg(2+) concentration, the solution color changes from greenish-blue, purple to red, which can be distinguished by the naked eye when the Hg(2+) concentration is higher than 250 nM. Owing to having a high surface-to-volume ratio and affinity toward Hg(0), the GNS is sensitive and selective (at least 50-fold over tested metal ions like Pb(2+)) toward Hg(2+) in the presence of AA. Practicality of this assay has been validated by the analysis of water samples without conducting tedious sample pretreatment. Frontiers Media S.A. 2018-11-27 /pmc/articles/PMC6277514/ /pubmed/30538981 http://dx.doi.org/10.3389/fchem.2018.00566 Text en Copyright © 2018 Xu, Yu, Yin, Wang, Lin and Yuan. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Chemistry
Xu, Dong
Yu, Shufang
Yin, Yueqin
Wang, Suyan
Lin, Qinlu
Yuan, Zhiqin
Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars
title Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars
title_full Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars
title_fullStr Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars
title_full_unstemmed Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars
title_short Sensitive Colorimetric Hg(2+) Detection via Amalgamation-Mediated Shape Transition of Gold Nanostars
title_sort sensitive colorimetric hg(2+) detection via amalgamation-mediated shape transition of gold nanostars
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6277514/
https://www.ncbi.nlm.nih.gov/pubmed/30538981
http://dx.doi.org/10.3389/fchem.2018.00566
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