Authors: A.A. Dawoud , T. Kawaguchi and R. Jankowiak
Affilation: Iowa State University, United States
Pages: 678 - 681
Keywords: microfluidic device, DNA-adducts, biomarkers, electroplating, nano-particles, electrochemistry
More sensitive and reliable microfluidic devices are needed for the detection of the 8-hydroxy-deoxyguanosine (8-OH-dG) DNA adduct, one of the most frequently used biomarkers reporting on oxidative stress. Therefore, we have developed a capillary electrophoresis based microfluidic device with electroplated palladium decoupler that provides significantly improved detection limit and separation efficiency. This has been accomplished using a PDMS/glass hybrid device with fully integrated gold microelectrodes covered in situ with palladium nanoparticles using electroplating technique. The quality of the electroplated decoupler was evaluated electrochemically and via SEM imaging. The performance of the device was tested and evaluated with different buffer systems at different pH and electric field strengths. The obtained results revealed significantly improved resolving power even when the separation electric field strength was as high as 600V/cm. The detection limit for the 8-OH-dG adduct is about 20 attomoles; the concentration detection limit is on the order of 100 nM (S/R = 3). A linear response is reported for detection of both 8-OH-dG and dG in the range of 100 nM - 100 uM with separation efficiency of about 120,000 -170,000 plates/m.