Arrays with individually addressable electrodes coated with ultra-thin DNA/enzyme films were evaluated to estimate relative rates of genotoxic bioactivation of various organic molecules for several different enzymes simultaneously. Specifically, cytochrome (cyt) P450cam, cyt P40 1A2 and myoglobin in the array were activated with hydrogen peroxide to metabolize benzo[a]pyrene (BP) and styrene to genotoxic metabolites. DNA damage by the metabolites was detected by increases in square wave voltammetric oxidation peaks using solution phase Ru(bpy)32+ or film imbedded [Ru(bpy)2(PVP)10]2+ metallopolymer as catalysts. Cyt P450cam and cyt P450 1A2 showed 3-fold higher activity for genotoxic bioactivation of BP than myoglobin. The detection of metabolite DNA damage through the simultaneous monitoring of electrochemiluminescence (ECL) intensity from the film imbedded metallopolymer along with voltammetric detection on the electrode arrays will also be discussed. The ability of the arrays to generate and detect metabolite-based DNA damage simultaneously for several biologically significant enzymes is a rapid and promising approach to identify and characterize enzymes involved in genotoxicity of drugs and pollutants.
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