Plasmonics at liquid-liquid interfaces
File(s)
Author(s)
Turek, Vladimir
Type
Thesis
Abstract
The PhD has studied gold nanoparticles (NPs) at the liquid-liquid interface (LLI). Some of the key aspects of the work are listed below.
• Centrifugation as a novel and efficient method for adsorbing a controlled number of NPs to the LLI.
• Controlled and tuneable 2D interparticle separation at the LLI as evidenced by the plasmon ruler.
• Reversible adsorption of 16 nm gold nanoparticles at the water-DCE interface.
• Centrifugation as a novel method to form an ultra-concentrated NP aqueous phase.
• Controlled and tuneable 3D inter-particle separation in water by ultra-concentration.
• The ultra-concentrated NP solution has some ‘record-breaking’ physical properties – e.g. densities in excess of 4.5 gcm-3; optical densities in excess of 70,000; and active surface areas of in excess of 70 m2/mL.
• Ultra-concentration is also demonstrated as an efficient purification and NP size-separation technique with efficiencies in excess of 99.9% and 99.5%, respectively.
• Close-packed NPs at the LLI are also demonstrated to be an efficient sensing platform through surface enhanced Raman spectroscopy.
• The platform benefits from: fmole detection limits; extremely facile, quick and cheap assembly; applicability to a wide range of target analytes; both hydrophilic and hydrophobic detection capabilities simultaneously.
• Through evaporation of the organic phase, the platform is also demonstrated to be able to identify and estimate concentrations of airborne analytes.
• Finally, 1,8-diaminonaphthalene and its analogues are demonstrated to be extremely efficient mercury reporters when combined with SERS at the LLI.
• A dramatic increase in SERS intensity is observed in the presence of mercury – though the exact reason for such an increase is still under investigation, some potential mechanisms are provided.
• As with other analytes, NPs at the liquid-air interface demonstrate airborne mercury detection capabilities and this is demonstrated for the first time using SERS.
• Centrifugation as a novel and efficient method for adsorbing a controlled number of NPs to the LLI.
• Controlled and tuneable 2D interparticle separation at the LLI as evidenced by the plasmon ruler.
• Reversible adsorption of 16 nm gold nanoparticles at the water-DCE interface.
• Centrifugation as a novel method to form an ultra-concentrated NP aqueous phase.
• Controlled and tuneable 3D inter-particle separation in water by ultra-concentration.
• The ultra-concentrated NP solution has some ‘record-breaking’ physical properties – e.g. densities in excess of 4.5 gcm-3; optical densities in excess of 70,000; and active surface areas of in excess of 70 m2/mL.
• Ultra-concentration is also demonstrated as an efficient purification and NP size-separation technique with efficiencies in excess of 99.9% and 99.5%, respectively.
• Close-packed NPs at the LLI are also demonstrated to be an efficient sensing platform through surface enhanced Raman spectroscopy.
• The platform benefits from: fmole detection limits; extremely facile, quick and cheap assembly; applicability to a wide range of target analytes; both hydrophilic and hydrophobic detection capabilities simultaneously.
• Through evaporation of the organic phase, the platform is also demonstrated to be able to identify and estimate concentrations of airborne analytes.
• Finally, 1,8-diaminonaphthalene and its analogues are demonstrated to be extremely efficient mercury reporters when combined with SERS at the LLI.
• A dramatic increase in SERS intensity is observed in the presence of mercury – though the exact reason for such an increase is still under investigation, some potential mechanisms are provided.
• As with other analytes, NPs at the liquid-air interface demonstrate airborne mercury detection capabilities and this is demonstrated for the first time using SERS.
Version
Open Access
Date Issued
2014-01
Date Awarded
2014-08
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Edel, Joshua
Kucernak, Anthony
Kornyshev, Alexei
Sponsor
Imperial College London
Engineering and Physical Sciences Research Council
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)