Supramolecular porphyrin arrays on DNA and SWNT scaffolds

A variety of supramolecular porphyrin arrays on DNA or single walled carbon nanotube scaffolds are presented herein. A novel porphyrin modified nucleoside with multiple degrees of freedom about the linking moiety has been synthesised. Oligonucleotide strands containing the novel ‘flexible’ porphyrin modified nucleoside or a previously published ‘rigid’ linked porphyrin modified nucleoside were synthesised. The resulting systems were analysed by photospectrometric techniques. Stable B form duplexes were observed in all cases, with the porphyrin modifications imparting a stabilising effect on the duplexes, the degree of stabilisation the novel porphryin monomer provides is of a similar level to that of the rigid linked monomer. Excitonic coupling of the porphyrins is observed; the different monomers incorporated into DNA show different effects in the circular dichroism spectra, which may be explained through the increased conformational freedom of the ‘flexible’ linker. The synthesis of a novel anthraquinone modified nucleoside is presented. Modified DNA strands containing both porphyrin modifications and anthraquinone modifications were synthesised and analysed electrochemically. Cyclic voltammetry has shown that the inclusion of multiple porphyrin modifications increase the electron transfer rate to the anthraquinone redox marker. The synthesese of a novel ferrocenyl modified nucleotide, a novel naphthalene diimide modified nucleotide and an alternative synthesis route for a ruthenium tris-bipyridyl nucleoside are presented. Homo- and hetero-porphyrin single walled carbon nanotube adducts have been prepared with neutral, tetra-anionic and tetra-cationic porphyrins. Significantly elevated loading levels have been observed for the mixed charge species which forms a 1:1 salt on the nanotube surfaces

Name dc:type.qualificationname

Ph.D.

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Southampton

Year dc:date.issued

2011

Author dc:creator

• Brewer, Ashley

Advisor dc:contributor.advisor

• Stulz, Eugen