Gold Nanoparticle-Assisted AFM Study of DNA Damage and Repair

The purpose of this research is to investigate gold nanoparticles as a potential scaffold for the characterization of DNA damage and repair using atomic force microscopy techniques. The procedure consists of functionalizing the surface of gold nanoparticles with DNA, which are then immobilized onto amine modified silicon or glass surfaces. The objective of this study is to examine various lesions in individual DNA molecules and follow their direct reversal by DNA repair enzymes through AFM imaging with the support of UV-vis spectrum results of the functionalized nanoparticles. In order to achieve this goal DNA repair proteins such as photolyase (repairs UV damaged thymine dimers in DNA using blue light energy) is used as damage markers and imaged in complexes with DNA by AFM in order to locate and identify the damage sites. The force spectroscopy measurements then determine the mechanical fingerprints of various types of DNA damage caused by UV and gamma radiation and directly follows damage reversal caused by photolyase repair activity.