The aim of this thesis is to develop a facile one-pot synthesis of silver nanoparticles (AgNPs) using Tollens' reagent as a silver source. The project focuses on the preparation of a series of sugar triazole ligands to template the formation of monodisperse AgNPs in a size- and shape-controlled manner. Chapter 1 introduces the optical properties of metal nanoparticles and the common methods for the preparation of AgNPs, highlighting the limitations of typical methods and the motivations of this research. Chapter 2 describes the influence of the structural parameters of these sugar triazole ligands (i.e., sugar units, triazole and aromatic core) on the size, shape, stability and dispersity of AgNPs. The work highlights how the Ag(I) binding affinity of these ligands is a key parameter to tune the size and shape of the resultant AgNPs formed. Weaker Ag(I) binding ligands with a phloroglucinol core form monodisperse angular AgNPs over a range of sizes (12 ± 1 nm - 33 ± 7 nm), whereas resorcinol core triazole ligands exhibiting a higher Ag(I) binding affinity produce monodisperse spherical AgNPs of a single size (8 ± 5 nm). Chapter 3 describes the synthesis of AgNPs using sugar triazole ligands and Tollens' reagent using silver trifluoroacetate to investigate the counter-ion effect of silver salts on the size and the morphology of formed AgNPs. This salt produces AgNPs with similar shapes and sizes compared to that formed using silver nitrate. Chapter 4 describes the synthesis of PEG-functionalised sugar triazoles bearing PEG groups to investigate their effects on the formation of AgNPs. This work identifies the southernmost triazole as a modular site to tune the size and shape of AgNPs. Installation of PEG chains into the southernmost triazole ring shows a significant reduction in the Ag(I) binding affinity and produces monodisperse angular AgNPs with diameters ranging from 15 ± 4 nm to 38 ± 7 nm.The surface enhanced Raman scattering properties of formed AgNPs are also discussed. Chapter 5 describes the synthesis of sugar-modified peptides to template the synthesis of AgNPs using Tollens' reagent. Increasing the sugar units using octamer peptide produces angular and smaller AgNPs (10 ± 2 - 23 ± 2) compared to that formed using pentamir peptide (16 ± 2 - 32 ± 4). In conclusion, this thesis reports a novel template-directed triazole ligand strategy for the one-step synthesis of AgNPs in a size- and shape-controlled fashion. The mild synthetic methodology outlined in this thesis opens up new opportunities for the development of optical biosensing and imaging applications.
|Date of Award||1 Aug 2014|
- University Of Strathclyde
|Supervisor||Glenn Burley (Supervisor)|