Signal enhancement of optical immunosensing by gold nanoparticles

Optical signals, such as surface plasmon resonance (SPR) angle, fluorescence intensity and quantum yield are commonly measured in optical immunosensing when an immunological interaction takes place between analytes and the specific bio-recognizable interface. Extensive researches on have been theref...

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Main Author: Yuan, Xintong
Other Authors: Robert Marks
Format: Theses and Dissertations
Language:English
Published: 2015
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Online Access:https://hdl.handle.net/10356/65564
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-655642023-03-04T16:49:03Z Signal enhancement of optical immunosensing by gold nanoparticles Yuan, Xintong Robert Marks Zhang Hua School of Materials Science & Engineering DRNTU::Engineering::Nanotechnology Optical signals, such as surface plasmon resonance (SPR) angle, fluorescence intensity and quantum yield are commonly measured in optical immunosensing when an immunological interaction takes place between analytes and the specific bio-recognizable interface. Extensive researches on have been therefore concentrated for decades to develop a more sensitive interface to lower the limit of detection. When the chromophores are in proximity to metal nanoparticles, gold nanoparticles (AuNPs) are capable of amplifying the signals by at least one order of magnitude. The enhancement factor is particularly dependent on the separation between the chromophores and surface of metallic nanoparticles, as well as the distribution of the electromagnetic field surrounding to the metallic nanoparticles. In this study, the fluorescence enhancement of Au-avidin-Texas Red conjugate was studied using multiple crosslinkers with different lengths. It was observed that in the presence of oligo-ethylene-glycol-based (OEG-based) crosslinkers not only was stability of gold nanoparticles against protein adsorption improved, but also fluorescence intensity was enhanced. The AuNPs intentionally capped with oligo ethylene glycol ligand will remain colloidal in high ionic strength up to 2mol/l. The fluorescence intensity was enhanced 3.8-fold when CT(PEG)7 was sandwiched at the length of 35.5A while 9-fold, in case that CT(PEG)12 was selected at specific length of 47.8A in the Au-avidin conjugate. It is predicted that such a multiplexing probe can be applied not only as a complementary substrate in SPR immunosensing but also as a fluorescence enhancer in the conventional fluorescence immunosensing. MASTER OF ENGINEERING (MSE) 2015-11-12T04:52:48Z 2015-11-12T04:52:48Z 2015 2015 Thesis Yuan, X. (2015). Signal enhancement of optical immunosensing by gold nanoparticles. Master's thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/65564 10.32657/10356/65564 en 83 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Nanotechnology
spellingShingle DRNTU::Engineering::Nanotechnology
Yuan, Xintong
Signal enhancement of optical immunosensing by gold nanoparticles
description Optical signals, such as surface plasmon resonance (SPR) angle, fluorescence intensity and quantum yield are commonly measured in optical immunosensing when an immunological interaction takes place between analytes and the specific bio-recognizable interface. Extensive researches on have been therefore concentrated for decades to develop a more sensitive interface to lower the limit of detection. When the chromophores are in proximity to metal nanoparticles, gold nanoparticles (AuNPs) are capable of amplifying the signals by at least one order of magnitude. The enhancement factor is particularly dependent on the separation between the chromophores and surface of metallic nanoparticles, as well as the distribution of the electromagnetic field surrounding to the metallic nanoparticles. In this study, the fluorescence enhancement of Au-avidin-Texas Red conjugate was studied using multiple crosslinkers with different lengths. It was observed that in the presence of oligo-ethylene-glycol-based (OEG-based) crosslinkers not only was stability of gold nanoparticles against protein adsorption improved, but also fluorescence intensity was enhanced. The AuNPs intentionally capped with oligo ethylene glycol ligand will remain colloidal in high ionic strength up to 2mol/l. The fluorescence intensity was enhanced 3.8-fold when CT(PEG)7 was sandwiched at the length of 35.5A while 9-fold, in case that CT(PEG)12 was selected at specific length of 47.8A in the Au-avidin conjugate. It is predicted that such a multiplexing probe can be applied not only as a complementary substrate in SPR immunosensing but also as a fluorescence enhancer in the conventional fluorescence immunosensing.
author2 Robert Marks
author_facet Robert Marks
Yuan, Xintong
format Theses and Dissertations
author Yuan, Xintong
author_sort Yuan, Xintong
title Signal enhancement of optical immunosensing by gold nanoparticles
title_short Signal enhancement of optical immunosensing by gold nanoparticles
title_full Signal enhancement of optical immunosensing by gold nanoparticles
title_fullStr Signal enhancement of optical immunosensing by gold nanoparticles
title_full_unstemmed Signal enhancement of optical immunosensing by gold nanoparticles
title_sort signal enhancement of optical immunosensing by gold nanoparticles
publishDate 2015
url https://hdl.handle.net/10356/65564
_version_ 1759854140507291648