Highly sensitive DNA-based electrochemical biosensor for analysis of oseltamivir used in treatment of COVID–19

Promising clinical results were obtained in the treatment of coronavirus disease by using favipiravir, umifenovir, remdesivir, ribavirin, lopinavir–ritonavir, oseltamivir, etc., antiviral drug active agents. In this study, quantitative analysis of oseltamivir neuraminidase inhibitor was carried out using electrochemical techniques. DNA-based electrochemical biosensors are generally used for analysis of anticancer and antitumor medicines. The present study introduces a novel DNA-based electrochemical sensor for neuraminidase inhibitor drug oseltamivir. The developed sensor enables the analysis of oseltamivir in a more environmentally friendly, more economical and faster way. It can be used in quality control laboratories in tablet production and will provide traceability of the drug in drug development studies and analysis in urine samples. For this purpose, a modified glassy carbon electrode was used as a working electrode. The glassy carbon electrodes alone cannot detect the oseltamivir. Guanine base, which was determined to interact with oseltamivir and found in the deoxyribonucleic acid structure, was used as an electrochemical biosensor agent. The guanine base was immobilized on glassy carbon electrode using glutardialdehyde as a crosslinker material and GA₂–Guanine/GCE electrode was achieved.

Two working ranges were determined for the Britton-Robinson buffer solution, tablet sample, and urine sample containing oseltamivir. The lowest detection limits (LODs) were calculated as 7.16 × 10⁻⁹ mol L⁻¹, 9.05 × 10⁻⁹ mol L⁻¹ and 6.19 × 10⁻⁶ mol L⁻¹ for Britton-Robinson buffer solution, tablet sample solution, and urine sample solution, respectively. The recovery ratio for the proposed sensor ranged between 86.6 and 103.5%.