An electrochemical sensor is described for the determination of nadifloxacin (NF). A glassy carbon electrode (GCE) was modified with amino-functionalized multiwalled carbon nanotubes and titanium dioxide nanoparticles. The modified GCE was characterized by electrochemical impedance spectroscopy, cyclic voltammetry and scanning electron microscopy. The electro-oxidation of NF follows a pH-dependent irreversible behavior. The effects of pH value, scan rate, supporting electrolyte, accumulation potential and accumulation time were optimized. Under optimum conditions and at a typical working potential of 600 mV (vs. Ag/AgCl), the adsorptive stripping voltammetric response is linear in the 5 nM to 5.0 μM NF concentration range. The limit of detection is 1.69 × 10−10 M in acidic solution of pH 1. The selectivity was investigated in the presence of 1–1000-fold concentrations of potentially interfering agents. Recoveries from cream formulations spiked with NF were performed to study precision and accuracy.
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