Thesis
Single nanoparticle surface-enhanced raman spectroscopy (SERS) measurements on electrode surfaces
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2025
- Thesis identifier
- T17491
- Person Identifier (Local)
- 201770114
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- Functionalised plasmonic nanoparticles provide exciting new opportunities to enhance both measurement sensitivity and spatial resolution across a wide range of electrochemical and optical analytical techniques. In particular, the electronic and chemical properties of gold nanoparticles can greatly facilitate optical surface-enhanced Raman scattering (SERS) measurements, which can be exploited to perform highly novel and challenging molecular and solid-state measurements on electroactive surfaces at nanoscale spatial resolutions. This capability could reveal further opportunities in the study of the heterogeneity of the battery potential surfaces at nanoscale spatial resolutions. In this thesis, the overall aim was to develop SERS-based sensors for in situ reporting in electroactive environments that are sufficiently robust and optically bright to enable highly localised confocal SERS mapping on electrode surfaces. Clearly demonstrating that these measurements can be performed in real-time at the level of single isolated nanoparticles is also a key aim of this work. Towards this goal, two distinct gold nanoparticle-based approaches were explored: i) the development of a novel polymer-based shell-isolated nanoparticle (SHIN) design involving a combination of molecular insulating layers surrounding a gold nanoparticle core, and ii) the preparation of inorganic shells of both Prussian Blue (PB) and Prussian Blue Analogues (PBA’s) around a gold nanoparticle core. In the first approach, a novel shell-isolated nanoparticle (SHIN) was designed and demonstrated for the first time. A key requirement is that the gold nanoparticle core enables SERS measurements of molecular species at an electrode surface while also ensuring that the gold core cannot participate in any electron or ion transfer reactions occurring as various potentials are applied. A novel combination of insulating layers were investigated for indirect potentiometric SERS sensing of a redox-active analyte on an electrode surface. The resultant SHINs demonstrated excellent single particle SERS, which was confirmed with correlated scanning electron microscopy (SEM), and enabled in situ SERS confocal electrode surface mapping at single nanoparticle sensitivities to be successfully demonstrated. In the second approach, Prussian Blue shell coated gold core nanoparticles (Au@PB NPs) were fabricated and their ability to sense localised changes in applied potential probed. In situ electrochemical investigations, combined with a ratiometric analysis allowed Au@PB NPs to indirectly determine the applied potential on an electrode surface. Combining in situ experiments with confocal microscopy allowed SERS mapping of individual nanoscale structures. The properties of Prussian Blue analogues (PBA) were also explored as a potential avenue to extend the potential window in which Au@PB NPs could be applied. The PBAs each exhibited distinct Raman spectra in response to changes in applied potential, potentially showing that a combination of Au@PB NPs and Prussian Blue analogue coated gold nanoparticles (Au@PBA NPs) could be utilised in a multiplexed approach.
- Advisor / supervisor
- Wark, Alastair
- Berlouis, Leonard
- Wain, Andy
- Resource Type
- DOI
- Embargo Note
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File | 2025-10-29 | Embargo |