Impedimetric aptasensor for kanamycin by using carbon nanotubes modified with MoSe2 nanoflowers and gold nanoparticles as signal amplifiers.

An aptamer based impedimetric method is described for the determination of kanamycin. A hydrothermal route was applied to synthesize molybdenum selenide nanoflowers (MoSe2) which are promising materials for use in sensing interfaces due to their high specific surface and excellent electrical conductivity. Carbon nanotubes were then decorated with the MoSe2 nanoflowers and gold nanoparticles (AuNP/CNT/MoSe2) and placed on a glassy carbon electrode to serve as a signal amplifier. An amino-terminal kanamycin-specific aptamer was covalently linked to carboxy groups of acid-oxidized CNTs on the electrode to act as the signalling probe. The various steps during the construction of the modified electrode were monitored by scanning electron microscopy, wavelength-dispersive and energy-dispersive X-ray spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. The change in electrochemical signal was quantified by electrochemical impedance spectroscopy, typically at a working voltage of 0.22 V vs. Ag/AgCl. The calibration plot is linear in the 1 pM-0.1 nM and 100 nM-10 μM kanamycin concentration range and has a 0.28 pM detection limit. The assay is outstandingly selective, sensitive, stable and reproducible. Graphical abstract ᅟ.