SERS enhancement of silver nanoparticles prepared by a template-directed triazole ligand strategy

Two advances in the development of a one-pot method to prepare silver nanoparticles (AgNPs) using the Tollens’ reagent are described. First, a template-directed process of AgNP synthesis using resorcinol triazole ligands bearing two pendent galactose sugars is shown. Second, the conversion of these AgNPs into SERS nanotags is demonstrated using malachite green isothiocyanate as the Raman reporter molecule

SERS enhancement of silver nanoparticles prepared by a template-directed triazole ligand strategy

Two advances in the development of a one-pot method to prepare silver nanoparticles (AgNPs) using the Tollens' reagent are described. First, a template-directed process of AgNP synthesis using resorcinol triazole ligands bearing two pendent galactose sugars is shown. Second, the conversion of these AgNPs into SERS nanotags is demonstrated using malachite green isothiocyanate as the Raman reporter molecule

Directed Metallisation Using Molecular Recognition Tools

During this thesis a new infrastructure of methods to template functional materials at specific sites in a DNA architecture using molecular recognition of specific DNA duplexes has been developed. The project focused on the use of naturally occurring duplex DNA and the Tollens’ reaction as a mild source of metal amenable to reduction in the presence of aldehyde functional groups. The advantages of this choice are: 1) The use of naturally-occurring DNA increases modularity; 2) The Tollens’ reagent acts as a mild selective metallising reagent that enables the reduction of metal ions at specific sites along DNA. Molecules such as Pyrrole-Imidazole polyamides were prepared and were tested to determine whether selective metallisation of DNA nano-architectures can be achieved by confining the nucleation and growth of silver nanostructures to defined regions along a DNA duplex

Directed metallisation using molecular recognition tools

During this thesis a new infrastructure of methods to template functional materials at specific sites in a DNA architecture using molecular recognition of specific DNA duplexes has been developed. The project focused on the use of naturally occurring duplex DNA and the Tollens’ reaction as a mild source of metal amenable to reduction in the presence of aldehyde functional groups. The advantages of this choice are: 1) The use of naturally-occurring DNA increases modularity; 2) The Tollens’ reagent acts as a mild selective metallising reagent that enables the reduction of metal ions at specific sites along DNA. Molecules such as Pyrrole-Imidazole polyamides were prepared and were tested to determine whether selective metallisation of DNA nano-architectures can be achieved by confining the nucleation and growth of silver nanostructures to defined regions along a DNA duplex.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Directed metallisation using molecular recognition tools

During this thesis a new infrastructure of methods to template functional materials at specific sites in a DNA architecture using molecular recognition of specific DNA duplexes has been developed. The project focused on the use of naturally occurring duplex DNA and the Tollens’ reaction as a mild source of metal amenable to reduction in the presence of aldehyde functional groups. The advantages of this choice are: 1) The use of naturally-occurring DNA increases modularity; 2) The Tollens’ reagent acts as a mild selective metallising reagent that enables the reduction of metal ions at specific sites along DNA. Molecules such as Pyrrole-Imidazole polyamides were prepared and were tested to determine whether selective metallisation of DNA nano-architectures can be achieved by confining the nucleation and growth of silver nanostructures to defined regions along a DNA duplex.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Highly efficient synthesis of DNA-binding hairpin polyamides via the use of a new triphosgene coupling strategy

A facile and highly efficient solid phase synthesis method is reported for the preparation of hairpin DNA-binding polyamides using the cost-effective triphosgene (BTC) activating agent. Difficult polyamide sequences were prepared from N-methylimidazole (Im) and N-methylpyrrole (Py) building blocks with high stepwise yields (>98%) using Boc chemistry. The versatility of the triphosgene coupling approach was also demonstrated for the first time on aryl hydrazine resins to afford biomedically relevant tail-truncated polyamides in excellent isolated yields

Highly efficient synthesis of DNA-binding polyamides using a convergent fragment-based approach

Two advances in the synthesis of hairpin pyrrole-imidazole polyamides (PAs) are described. First, the application of a convergent synthetic strategy is shown, involving the Boc-based solid phase synthesis of a C-terminal fragment and the solution phase synthesis of the N-terminal fragment. Second a new hybrid resin is developed that allows for the preparation of hairpin PAs lacking a C-terminal beta-alanine tail. Both methods are compatible with a range of coupling reagents and provide a facile, modular route to prepare PA libraries in high yield and crude purity

Substituents on Quinone Methides Strongly ModulateFormation and Stability of Their Nucleophilic Adducts

Electronic perturbation of quinone methides (QM) greatly influences their stability and in turn alters the kinetics and product profile of QM reaction with deoxynucleosides. Consistent with the electrondeficient nature of this reactive intermediate, electron-donating substituents are stabilizing and electronwithdrawing substituents are destabilizing. For example, a dC N3-QM adduct is made stable over the course of observation (7 days) by the presence of an electron-withdrawing ester group that inhibits QM regeneration. Conversely, a related adduct with an electron-donating methyl group is very labile and regenerates its QM with a half-life of approximately 5 h. The generality of these effects is demonstrated with a series of alternative quinone methide precursors (QMP) containing a variety of substituents attached at different positions with respect to the exocyclic methylene. The rates of nucleophilic addition to substituted QMs measured by laser flash photolysis similarly span 5 orders of magnitude with electron-rich species reacting most slowly and electron-deficient species reacting most quickly. The reversibility of QM reaction can now be predictably adjusted for any desired application