Ultrasensitive electrochemical determination of metronidazole based on polydopamine/carboxylic multi-walled carbon nanotubes nanocomposites modified GCE.

An ultrasensitive electrochemical sensor based on polydopamine/carboxylic multi-walled carbon nanotubes (MWCNTs-COOH) nanocomposites modified glassy carbon electrode (GCE) was presented in this work, which has been developed for highly selective and highly sensitive determination of an antimicrobial drug, metronidazole. The preparation of polydopamine/MWCNTs-COOH nanocomposites/GCE sensor is simple and possesses high reproducible, where polydopamine can be coated on the surface of MWCNTs-COOH via a simple electropolymerization process. Under optimized conditions, the proposed sensor showed ultrasensitive determination for metronidazole with a wide linear detection range from 5 to 5000 µmol/dm3 and a low detection limit of 0.25 µmol/dm3 (S/N = 3). Moreover, the proposed sensor has been successfully applied for the quantitative determination of metronidazole in real drug samples. This work may provide a novel and effective analytical platform for determination of metronidazole in application of real pharmaceutical and biological samples analysis.