Detection of UV-Induced Mutagenic Thymine Dimer Using Graphene Oxide

Abstract

In this paper, we report for the first time that graphene oxide (GO) can interact with mutagenic DNA but not intact DNA. After UV-irradiated fluorophore-linked DNA containing thymine repeats was mixed with GO, a decrease in fluorescence was observed in a time-dependent manner. In contrast, no fluorescence change was observed with intact DNA, indicating that UV irradiation of DNA resulted in the formation of mutagenic bases. Because GO is known to act as a fluorescence quencher, the decreased fluorescence implies adsorption of the UV-irradiated DNA onto GO. It appears that the decreased fluorescence might result from the greater accessibility of hydrophobic methyl groups and phenyl rings of thymine dimers to GO and from deformed DNA structures with less effective charge shielding under salt-containing conditions. Using this affinity of GO for mutagenic DNA, we could detect UV-irradiated DNA at concentrations as low as 100 pM. We were also able to analyze the ability of phototoxic drugs to catalyze the formation of mutagens under UV irradiation with GO. Because our method is highly sensitive and feasible and does not require the pretreatment of DNA, we propose that it could accelerate the screening of potential phototoxic drug candidates that would be able to sensitize mutagenic dsDNA.

Fast and simple method for screening of single-stranded DNA breaking photosensitizers using graphene oxide

“…However, it was reported that purine dimers formed between two adenines and between adjacent purines and pyrimidines [ 24 ]. Previously, it was reported that formation of dimers within DNA increased affinity of GO to the mutated DNA [ 19 ]. No significant changes in DOF of the GO-DNA mixtures in the absence of KP even after 40 min of irradiation with UV light confirmed no noticeable formation of purine dimers.…”

“…Due to the selective affinity to ssDNA, and highly effective fluorescence quenching ability, GO has been applied to detect various targets such as heavy metals, small molecules and nucleic acids [ 18 ]. Previously, a GO based method to detect DNA photodimers and screen dimer-photosensitizing drugs was reported [ 19 ]. However, it is not yet reported if GO could be applied to detect the SDBs and screen photosensitizing drugs.…”

Detection of UVA/UVC-induced damage of p53 fragment by rolling circle amplification with AIEgens

“…19 Traditional fluorescent methods make it difficult to get good sensitivity and a high signal-to-background ratio. [20][21][22] Thus, the development of a simple, convenient and sensitive method to detect the damage of DNA by UV radiation is highly desirable.…”