Voltammetric microwell array for oxidized guanosine in intact ds-DNA.

Oxidative stress in humans causes damage to biomolecules by generating reactive oxygen species (ROS). DNA can be oxidatively damaged by ROS, which may lead to carcinogenesis. Here we report a microfluidic electrochemical array designed to rapidly detect oxidation in intact DNA in replicate measurements.

Assessing DNA Damage from Enzyme-Oxidized Single-Walled Carbon Nanotubes.

Peroxidase enzyme digests of oxidized single-wall carbon nanotubes (SWCNT) were shown to damage DNA in potentially genotoxic reactions for the first time using an electro-optical array with and without metabolic activation.

Genotoxicity-related chemistry of human metabolites of benzo[ghi]perylene (B[ghi]P) investigated using electro-optical arrays and DNA/microsome biocolloid reactors with LC-MS/MS.

There is limited and sometimes contradictory information about the genotoxicity of the polycyclic aromatic hydrocarbon benzo[ghi]perylene (B[ghi]P). Using recently developed metabolic toxicity screening arrays and a biocolloid reactor-LC-MS/MS approach, both featuring films of DNA and human metabolic enzymes, we demonstrated the relatively low reactivity of metabolically activated B[ghi]P toward DNA. Electro-optical toxicity screening arrays showed that B[ghi]P metabolites damage DNA at a 3-fold lower rate than benzo[a]pyrene (B[a]P), whose metabolites have a strong and well-understood propensity for DNA damage.

Evaluation of electrochemiluminescent metabolic toxicity screening arrays using a multiple compound set.

Arrays for screening metabolite-generated toxicity utilizing spots containing DNA, enzyme, and electroluminescent (ECL) polymer ([Ru(bpy)(2)PVP(10)](2+)) were extended to include a fully representative set of metabolic enzymes from human and rat liver microsomes, human and rat liver cytosol, and mouse liver S9 fractions. Array use involves two steps: (1) enzyme activation of the test chemical and metabolite reaction with DNA, and then, (2) capture of ECL resulting from DNA damage using a charge coupled device (CCD) camera. Plots of ECL increase vs enzyme reaction time monitor relative rates of DNA damage and were converted into turnover rates for enzymic production of DNA-reactive metabolites.

Electrochemiluminescent immunosensor for detection of protein cancer biomarkers using carbon nanotube forests and [Ru-(bpy)(3)](2+)-doped silica nanoparticles.

We report the first electrochemiluminescent immunosensor combining single-wall carbon nanotube forests with RuBPY-silica-secondary antibody nanoparticles for sensitive detection of cancer biomarker prostate specific antigen.

Comparison of DNA-Reactive Metabolites from Nitrosamine and Styrene Using Voltammetric DNA/Microsomes Sensors.

Voltammetric sensors made with films of polyions, double-stranded DNA and liver microsomes adsorbed layer-by-layer onto pyrolytic graphite electrodes were evaluated for reactive metabolite screening. This approach features simple, inexpensive screening without enzyme purification for applications in drug or environmental chemical development. Cytochrome P450 enzymes (CYPs) in the liver microsomes were activated by an NADPH regenerating system or by electrolysis to metabolize model carcinogenic compounds nitrosamine and styrene.