A novel modified carbon paste electrode is prepared as an electrochemical sensor for simultaneous determination of levodopa (LD) and acetaminophen (AC) in the presence of ascorbic acid (AA).Response Surface Methodology (RSM) was used to optimize voltammetric responses of modified electrode for determination of LD and AC. Thecentral composite design (CCD) as a response surface approach was applied for obtaining theoptimum conditions as well as the maximum heights of LD and AC oxidation peaks(1).Under the optimum condition the DPV data showed that the obtained anodic peak currents were linearly dependent on the LD and AC concentrations in the range of 0.3–700 and 0.1–500 μmol L−1, respectively. The applicability of the modified electrode was demonstrated by simultaneous determination of LD and AC in human serum.In this work for the first time a carbonpaste electrode (CPE) modified with multi-walled carbon nanotube,TiO2 hollow spheres and polyaspartic acid film (P-ASP / TiO2 hollow spheres –MWCNTs/CPE) was used as a sensitive sensor for simultaneous determinations of LD and AC. TiO2 hollow spheres was synthesized in our laboratory using by liquid phase deposition.Fig. 1 shows a typical image of the TiO2 hollow spheres.
