Microfluidic array for simultaneous detection of DNA oxidation and DNA-adduct damage

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biotechnology

Background:

• Chemical pollutants and pharmaceuticals can cause health issues via metabolite-induced toxicity.
• Detecting DNA damage, such as oxidation and adduct formation, is crucial for assessing these risks.
• Conventional methods for DNA damage detection are often expensive, slow, and complex.

Purpose of the Study:

• To develop a novel microfluidic electrochemical sensor array for simultaneous detection of DNA oxidation and nucleobase adduct formation.
• To provide a rapid, cost-effective, and simplified method for screening metabolic-genotoxic chemicals.
• To enable direct measurement of DNA damage in unhydrolyzed DNA.

Main Methods:

• Fabrication of an 8-electrode screen-printed carbon array coated with metallopolymers (OsPVP, RuPVP), DNA, and metabolic enzymes using layer-by-layer electrostatic assembly.
• A reaction step where test chemicals and reagents flow over the array.
• Selective electrochemical detection of oxidized guanines by OsPVP and DNA adduction by metabolites by RuPVP.

Main Results:

• The sensor array successfully detected both DNA oxidation and adduct formation in a single run.
• Demonstrated array performance for various test chemicals including 17β-estradiol and its metabolites, NNK, and 2-AAF.
• Achieved a detection limit of 672 8-oxodG per 10^6 bases for oxidation and 15 pg (∼10 pmol) for mass detection.

Conclusions:

• The developed microfluidic sensor array offers a faster, simpler, and less expensive alternative to conventional methods for DNA damage detection.
• This technology enables a comprehensive metabolic-genotoxic chemistry screen, directly measuring damage in unhydrolyzed DNA.
• The array has significant potential for assessing health risks associated with exposure to chemical pollutants and pharmaceuticals.