Huang, Jingle;
(2025)
Gold and Silver Nanoparticle Based
Colorimetric Sensing Method.
Doctoral thesis (Ph.D), UCL (University College London).
![[thumbnail of PhD Thesis Jingle HUANG.pdf]](https://discovery.ucl.ac.uk/style/images/fileicons/text.png) |
Text
PhD Thesis Jingle HUANG.pdf - Submitted Version Access restricted to UCL open access staff until 1 June 2026. Download (6MB) |
Abstract
This thesis explores the application of gold (AuNPs), and silver nanoparticle (AgNPs) based colorimetric sensing probes in medical diagnostics, environmental monitoring, and molecular recognition. These systems were designed to detect salivary creatinine, silver ions in water, and specific analytes using cucurbituril-AuNP aggregates. First, citrate-capped AgNPs were synthesised as probes for detecting creatinine in artificial saliva. In the presence of additional silver ions, their interaction with creatinine triggered significant nanoparticle aggregation, resulting in a visible colour change from pale yellow to blue grey. This colour shift was quantified using UV-Vis spectroscopy, enabling the detection of creatinine at nanomolar concentrations. Secondly, cytosine-functionalised AuNPs were developed to detect silver ions in tap water. The detection mechanism involved the formation of cytosine-Ag-cytosine pairs, which caused the nanoparticles to transition from a dispersed to an aggregated state. This transition induced a colour change from red to deep blue, which was measured using an RGB (red, green, and blue) sensor system or UV-Vis spectroscopy. Finally, a supramolecular system of cucurbituril-AuNP nanoaggregates was created for molecular recognition and quantitative analysis. A novel approach was employed, recording UV-Vis spectra at fixed time intervals. The collected data were integrated to determine the rate of extinction changes at the absorption peak over time. Different analytes and their derivatives displayed distinct functional relationships at the same concentration, while individual analytes exhibited unique rates when their concentrations varied. This method was further evaluated for detecting uric acid in artificial urine, achieving nanomolar-level sensitivity. The three studies presented in this thesis highlight the potential of AuNPs and AgNPs in developing advanced sensing strategies, laying the groundwork for future innovations in plasmonic nanomaterial-based sensors.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Gold and Silver Nanoparticle Based Colorimetric Sensing Method |
| Language: | English |
| Additional information: | Copyright © The Author 2025. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10208086 |
Archive Staff Only
 |
View Item |
