Abstract
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 mu L 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.