Developing a sensitive DNA biosensor for the detection of flutamide using electrochemical method

An uncomplicated method was applied to fabricate a novel electrochemical DNA biosensor for the determination of flutamide. This biosensor was composed of pretreated screen-printed electrode (SPE) that was modified with reduced graphene oxide (rGO) and decorated with ds-DNA. This biosensor was applied via the interaction of small molecules such as flutamide with the DNA. The interaction of salmon sperm ds-DNA with flutamide on the surface of ds-DNA-modified rGO-SPE (ds-DNA/rGO/SPE) was examined. The oxidation currents of guanine and adenine were used as probes in order to peruse the resulting interaction. Through the interaction of flutamide with the DNA, the oxidation currents of guanine and adenine declined at the ds-DNA/rGO/SPE, using differential pulse voltammetry (DPV). There was a linear dependence of the adenine oxidation currents and the flutamide concentration in the range of 0.0025-0.075 and 0.075-7.50 nmol L-1, with a limit of detection 1.5 pmol L-1. The relative standard deviations (RSD) for five replicate measurements of 0.05 and 5.0 nmol L-1 flutamide were obtained as 4.5 and 3.5%, using the adenine signal. This method was successfully applied to determine the trace amount of flutamide in real samples.