Electrospinning in the preparation of an electrochemical sensor based on carbon nanotubes

This paper reports the development of an electrochemical sensor using electrospun polymeric fibers of PBAT (poly (butylene adipate co-terephthalate))/PLA (poly (lactic acid) containing functionalized carbon nanotubes (MWCNTs) and further calcined (at 500 °C under N2). The morphologies of the electrospun fibers were verified by SEM and those containing MWCNTs presented lower average diameter of 1.76 ± 0.30 μm against 3.67 ± 0.88 μm for the fibers of neat PBAT/PLA. Fourier transform infrared (FTIR) spectra of the polymeric fibers indicated possible interactions between the MWCNTs and the CO functional group. Thermogravimetric analysis (TGA) curves demonstrated slight increase of the stability of the PLA and lower thermal stability of the PBAT. Analyzes through differential scanning calorimetry (DSC) data showed that the interactions occur preferentially with the aliphatic segments of polymer chains; and corroborated the data from FTIR. Also, FTIR and X-ray powder diffraction (DRX) indicated, respectively, decrease on carboxylic groups amount and lamella formation on functionalized MWCNTs due to the PBAT/PLA/MWCNTs electrospun fibers calcination. The electrochemical measurements performed using sensor built based on the as-obtained calcined material showed that the sensor is promising for the determination of metronidazole in aqueous environment.