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 à 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 from5 to 5000 mmol/dm^3 and a low detection limit of 0.25 mmol/dm^3(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.

Molecularly imprinted sensor based on carboxylated carbon nanotubes/Keggin-type polyoxometalates nanocomposite for the detection of furazolidone

Due to its properties of mutagenic,teratogenic,and carcinogenic,the detection of furazolidone(FZD)in aquaculture is of great importance for food safety and human health.In this study,molecularly imprinted fi lms modifi ed with carboxylated multi-walled carbon nanotube-phosphomolybdic acid composite were used to fabricate an electrochemical sensor for the determination of FZD.The nanocomposites were characterized using infrared spectroscopy,scanning electron microscopy,energy-dispersive X-ray spectroscopy,and X-ray diff raction.The electrochemical characteristics of the modifi ed electrodes were examined using electrochemical impedance spectroscopy,cyclic voltammetry,and diff erential pulse voltammetry.The sensor exhibited exceptional catalytic performance.The calibration curves were acquired in the concentration range of 6 nmol·L^(−1)to 0.6μmol·L^(−1),with a limit of detection of 3.38 nmol·L^(−1).Additionally,the sensor proved successful in recognizing FZD in shrimp samples with satisfactory recoveries and precision.The method provides a strategy to construct a molecularly imprinted electrochemical sensing platform using nanomaterials,which has great promise in the field of food safety.