Batch Injection Analysis with Amperometric Detection for DNA Biosensing Applications

In this work, batch injection analysis with the amperometric detection (BIA‐AD), employing a detection cell designed to adapt a screen‐printed carbon electrode (SPCE) was used for the first time as a robust electroanalytical system for DNA biosensing applications. The sensitive amperometric detection was used to evaluate the structural changes in double‐stranded DNA (dsDNA) after UV‐C irradiation of its solution for a given time. Batching of DNA samples was performed by precise electronic pipette microinjection of an irradiated sample aliquot onto the unmodified activated SPCE surface incorporated in the BIA‐AD system. Using the optimized experimental conditions (40 μL of 1 mg mL^?1 dsDNA in a 0.1 M phosphate buffer of pH 7.4 sampled at the injection speed degree of 6 and detected at the potential of +1.5 V vs silver pseudo‐reference electrode), a time‐dependent response (gradual decrease of amperometric signal up to 58 % after 10 min of the irradiation) was found for the detection of damage to low molecular weight salmon sperm dsDNA. The advantages of this low‐dimensional and cost‐effective measuring system can be utilized not only for the quantification of DNA damage/degradation by UV irradiation, but they are also promising for studying other types of DNA interactions.