Photonic Transfer in DNA Nano Construct
- Author(s): Golkar Narenji, Alaleh
- Advisor(s): Heller, Michael
- et al.
A significant amount of work has been done to improve design and fabrication of DNA constructs with photonic and electronic transfer properties. In this thesis, we evaluated the prior work for both electronic and photonic transfer. While DNA constructs with first-order fluorescent resonant energy transfer (FRET) properties have proven useful, incorporation of higher-order FRET and electronic properties into DNA has not yet led to any viable applications. In this thesis, we generated 35 base pairs long double-stranded (ds) DNA structures with different arrangements of five TAMRA donor dyes and a single TexasRed acceptor. In these constructs the distance of the distal donor dyes to the acceptor is greater than 1.7 nm or five base pairs (which is beyond the optimal FRET distance). The average FRET efficiency of these double stranded systems based on the donor intensity change and the acceptor-to-donor ratio of intensity change was 66% and 26%, respectively. Addition of surfactants and metal cations reduced quenching and enhanced the FRET efficiency of these DNA structures. After adding the surfactant and metal cations, the average FRET efficiency of these ds-systems based on the donor intensity change and the acceptor-to-donor ratio of intensity change was 89% and 75%, respectively.
We also reviewed the conductivity properties of DNA and how it is influenced by temperature, UV illumination and GC content. Results from literature indicate that temperature significantly changes DNA conductivity. Moreover, the UV exposure experiments indicate a decrease in DNA conductivity due to damage of GC base pairs and the phosphate group. We also investigated the effect of nucleotide content on DNA conductivity and we showed that the higher GC content results in higher conductivity.