DNA electrochemical biosensor for metallic drugs at physiological conditions

[Display omitted] •Design of single use, disposable biosensor for titanocene dichloride.•Double stranded SS-DNA can be electrochemically entrapped into the PPy–PVS matrix.•dsSS-DNA–PPy–PVS/ITO biosensor can detect titanocene in micromolar quantities. Entrapment of dsSS-DNA into the polypyrrole–polyvinyl sulfonate (dsSS-DNA–PPy–PVS) film over indium-tin-oxide (ITO) coated glass has been designed to detect titanium and platinum drugs, titanocene dichloride and cisplatin. The disposable dsSS-DNA–PPy–PVS/ITO biosensor was characterized by cyclic voltammetry, attenuated total reflectance Infrared spectroscopy and atomic force microscopy. Amperometric studies by cyclic voltammetry using, dsSS-DNA–PPy PVS/ITO biosensor, demonstrated the ability of this biosensor to detect these metallic drugs in millimolar concentration by monitoring the decrease of the guanine oxidation signal as a result of the DNA damage. The concentration range detected for titanocene dichloride is 0.25–1.5mM and for cisplatin is 0.06–1.0mM.