Selective Electrochemical Detection of Pirarubicin by Means of DNA-Modified Graphite Biosensor

Pirarubicin (THP) is an anthracycline drug, which is mainly used in the anticancer treatment. Utilization of THP may be associated with many dangerous side effects, therefore monitoring of drug level in patients' organism is an important aspect of chemotherapy. In our research we focused on designing of an electrochemical DNA-based biosensor for selective detection of pirarubicin (THP). Our biosensor utilizes the ability of pirarubicin to interact with DNA double helix and the fact that THP is an electrochemically active compound. Graphite electrodes modified with DNA enable to obtain nearly three thousand times higher sensitivity (41.810(3)A/M) than non-modified sensors. Furthermore, in the case of THP detection by means of bare graphite electrodes, LOD was 43.610(-9)M, whereas for developed DNA biosensors -11210(-12)M. A study of selectivity of DNA-modified biosensors was carried out in aqueous solutions containing interferents: acetaminophen (PCT) and ascorbic acid (AA) as well as in samples of fetal bovine serum (FBS) spiked with PCT and AA. In established measurement conditions one peak corresponding to THP reduction was observed, whereas no redox peaks assigned to interferents (PCT, AA) were present. These results indicate that developed biosensors are selective to pirarubicin.