An Ultrasensitive Electrochemical DNA‐Nano Biosensor for Monitoring Tirapazamine as Anticancer Drug Using Zno/Co3O4 Nanocomposite

Abstract In this study, we used a screen‐printed electrode (SPE) modified with polypyrrole (PP), ZnO/Co 3 O 4 nanocomposite, and ds‐DNA as an extremely sensitive DNA biosensor to monitor tirapazamine (TPZ) real samples. To build the ds‐DNA/PP/ZnO/Co 3 O 4 NC/SPE biosensor, the layer‐by‐layer manufacturing process was used. The proper alteration of the SPE surface as well as the effective fabrication of the ZnO/Co 3 O 4 nanocomposite were both validated by the physicochemical characterization techniques. As a result of improving its conductivity of electricity along with allowing charged particles to move more easily, the modified SPE demonstrated much decreased the resistance of charge transfer based on the results of electrochemical impedance spectroscopy. With the 0.43 nM LOD value, the suggested biosensor effectively measured TPZ throughout a broad concentration between 0.001 and 120 µM. Additionally, the molecular docking investigation among the TPZ molecule as well as the DNA was conducted to anticipate the TPZ contact sites with DNA and verified the experimental results. By combining the benefits of ZnO/Co 3 O 4 nanocomposite with vital information from the molecular docking investigation, the current research lays the door for the creation of very sensitive DNA biosensors, which can be utilized to track and measure TPZ of real samples.