Hybrid Nanostructures (HNS)
Decomposition of halogenated nucleobases
Decomposition of halogenated nucleobases by surface plasmon resonance excitation of gold nanoparticles
T. S. Marques; M. Śmiałek; R. Schürmann; I. Bald; M. Raposo; S. Eden N. Mason
Halogenated uracil derivatives are of great interest in modern cancer therapy, either aschemotherapeutics or radiosensitisers depending on their halogen atom. This work applies UV-Vis spec-troscopy to study the radiation damage of uracil, 5-bromouracil and 5-fluorouracil dissolved in water inthe presence of gold nanoparticles upon irradiation with an Nd:YAG ns-pulsed laser operating at 532 nmat different fluences. Gold nanoparticles absorb light efficiently by their surface plasmon resonance andcan significantly damage DNA in their vicinity by an increase of temperature and the generation of re-active secondary species, notably radical fragments and low energy electrons. A recent study using thesame experimental approach characterized the efficient laser-induced decomposition of the pyrimidine ringstructure of 5-bromouracil mediated by the surface plasmon resonance of gold nanoparticles. The presentresults show that the presence of irradiated gold nanoparticles decomposes the ring structure of uracil andits halogenated derivatives with similar efficiency. In addition to the fragmentation of the pyrimidine ring,for 5-bromouracil the cleavage of the carbon-halogen bond could be observed, whereas for 5-fluorouracilthis reaction channel was inhibited. Locally-released halogen atoms can react with molecular groups withinDNA, hence this result indicates a specific mechanism by which doping with 5-bromouracil can enhanceDNA damage in the proximity of laser irradiated gold nanoparticles.
Journal Article