Fatih DONMEZ, Burak KUZU, Hasret SUBAK
Journal of Research in Pharmacy - 2026;30(2):629-643
This study aims to develop a voltammetric biosensor to investigate the interaction between the quinolone antibiotic levofloxacin (LVX) and double -stranded DNA (dsDNA) by combining electrochemical and molecular docking approaches. The development process in volved characterising the electrochemical behaviour of LVX, analysing the LVX -DNA interaction, and exploring the binding mechanism and interaction region in silico using molecular docking techniques . Square wave voltammetry (SWV) was performed wi th a pencil graphite electrode (PGE) to monitor the oxidation signals of DNA bases, particularly deoxyguanosine and deoxyadenosine, in both the presence and absence of LVX. Additionally, the electrochemical response of LVX alone was examined , and its interaction with DNA was evaluated based on variations in peak currents. The effects of interaction time, pH , and drug concentration on binding behaviour were systematically investigated. LVX was determined within the concentration range of 0.5 -20 µg/mL, and under optimised conditions, a limit of detection (LOD) of 0.0074 µg/mL ( 0.206 µM ) was achieved. The reproducibility of the dsDNA biosensor was confirmed by relative standard deviations (RSD%) of 5.20%, 4.52% , and 5.38% for the oxidation peaks of guanine, LVX, and LVX -DNA, respectively. Molecular docking results indicated that LVX primarily interacts with dsDNA through groove binding, which is predominantly stabilised by hydrogen bonding. The electrochemical fi ndings were in good agreement with the molecular d ocking outcomes, providing comprehensive insight into the binding mechanism and confirming that the LVX -DNA interaction is both specific and measurable under the tested conditions.
