Detection of Environmental DNA Damage Using Electrochemical Sensors and Mass Spectrometry

Nickel exposure has been linked to a variety of health complications including instances of tumors and cancer in living organisms. Exposure to nickel can occur due to pollution from mining or industrial applications. Ingested nickel has been shown to be toxic and a promoter of DNA damage through direct and indirect interactions with DNA systems. Since the outcomes of nickel toxicity are well documented , it is advantageous to develop ways to assay the amount of DNA damage that has occurred after exposure and the mechanisms detailing how nickel interacts with DNA systems. Nematodes , primarily C. elegans and P. pacificus , have been used as model organisms to study the biological effects of environmental pollutants like nickel. Since the replication , transfer , and repair of DNA is a highly sophisticated and constantly evolving process , there is good reason to suspect that environment could play a key role in an organisms response to nickel. DNA from nematodes obtained in both high nickel and typical cosmopolitan environments was compared to discern any change in the amount of damage incurred from identical nickel concentrations provided in vitro. Genomic damage was assayed via electrochemical sensors prepared by incorporating DNA in a Layer-by-Layer (LbL) assembly. A variety of strains from Hawaii , New Zealand , England , and Pasadena were assayed after each had been exposed to increasing concentrations of nickel. Hawaii and New Zealand are environments with naturally high amounts of nickel due to volcanic activity. Our studies show a strong correlation between nickel exposure and DNA damage that is not only concentration dependent but influenced by the environmental conditions from which the nematodes originated. Mass spectrometry was also employed to highlight the types and increases in DNA nucleobase biomarkers that are used to characterize certain types of DNA damaging reactions. This provides specific information towards the way nickel alters DNA and how biological adaptation plays a role in genomic protection from exogenic toxins