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Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules
Fluorescence titration of methylene blue, rhodamine B and rhodamine 6G (R6G) by silver nanoparticle (AgNP) all resulted in an initial steep quenching curve followed with a sharp turn and a much flatter quenching curve. At the turn, there are about 200,000 dye molecules per a single AgNP, signifying...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6720720/ https://www.ncbi.nlm.nih.gov/pubmed/31416283 http://dx.doi.org/10.3390/ma12162592 |
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author | Deng, Hua Yu, Hongtao |
author_facet | Deng, Hua Yu, Hongtao |
author_sort | Deng, Hua |
collection | PubMed |
description | Fluorescence titration of methylene blue, rhodamine B and rhodamine 6G (R6G) by silver nanoparticle (AgNP) all resulted in an initial steep quenching curve followed with a sharp turn and a much flatter quenching curve. At the turn, there are about 200,000 dye molecules per a single AgNP, signifying self-assembly of approximately 36-layers of dye molecules on the surface of the AgNP to form a micelle-like structure. These fluorescence-quenching curves fit to a mathematical model with an exponential term due to molecular self-assembly on AgNP surface, or we termed it “self-assembly shielding effect”, and a Stern-Volmer term (nanoparticle surface enhanced quenching). Such a “super-quenching” by AgNP can only be attributed to “pre-concentration” of the dye molecules on the nanoparticle surface that yields the formation of micelle-like self-assembly, resulting in great fluorescence quenching. Overall, the fluorescence quenching titration reveals three different types of interactions of dye molecules on AgNP surface: 1) self-assembly (methylene blue, rhodamine B and R6G), 2) absorption/tight interaction (tryptamine and fluorescein), and 3) loose interaction (eosin Y). We attribute the formation of micelle-like self-assembly of these three dye molecules on AgNP to their positive charge, possession of nitrogen atoms, and with relatively large and flat aromatic moieties. |
format | Online Article Text |
id | pubmed-6720720 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-67207202019-09-10 Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules Deng, Hua Yu, Hongtao Materials (Basel) Article Fluorescence titration of methylene blue, rhodamine B and rhodamine 6G (R6G) by silver nanoparticle (AgNP) all resulted in an initial steep quenching curve followed with a sharp turn and a much flatter quenching curve. At the turn, there are about 200,000 dye molecules per a single AgNP, signifying self-assembly of approximately 36-layers of dye molecules on the surface of the AgNP to form a micelle-like structure. These fluorescence-quenching curves fit to a mathematical model with an exponential term due to molecular self-assembly on AgNP surface, or we termed it “self-assembly shielding effect”, and a Stern-Volmer term (nanoparticle surface enhanced quenching). Such a “super-quenching” by AgNP can only be attributed to “pre-concentration” of the dye molecules on the nanoparticle surface that yields the formation of micelle-like self-assembly, resulting in great fluorescence quenching. Overall, the fluorescence quenching titration reveals three different types of interactions of dye molecules on AgNP surface: 1) self-assembly (methylene blue, rhodamine B and R6G), 2) absorption/tight interaction (tryptamine and fluorescein), and 3) loose interaction (eosin Y). We attribute the formation of micelle-like self-assembly of these three dye molecules on AgNP to their positive charge, possession of nitrogen atoms, and with relatively large and flat aromatic moieties. MDPI 2019-08-14 /pmc/articles/PMC6720720/ /pubmed/31416283 http://dx.doi.org/10.3390/ma12162592 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Deng, Hua Yu, Hongtao Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules |
title | Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules |
title_full | Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules |
title_fullStr | Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules |
title_full_unstemmed | Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules |
title_short | Silver Nanoparticle Surface Enabled Self-Assembly of Organic Dye Molecules |
title_sort | silver nanoparticle surface enabled self-assembly of organic dye molecules |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6720720/ https://www.ncbi.nlm.nih.gov/pubmed/31416283 http://dx.doi.org/10.3390/ma12162592 |
work_keys_str_mv | AT denghua silvernanoparticlesurfaceenabledselfassemblyoforganicdyemolecules AT yuhongtao silvernanoparticlesurfaceenabledselfassemblyoforganicdyemolecules |