The synthesis of functional nanomaterials with unique structures and morphologies as efficient biocatalysts for sensing application has attracted tremendous interest. Herein, Fe3C nanoparticles encapsulated within nitrogen-doped carbon (Fe3C/N–C) nanofibers have been prepared through a facile electrospinning strategy and a carbonization process. The resulting Fe3C/N–C hybrid nanofibers display a superior oxidase-like performance toward the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) and other substrates, which is dependent on the formation of Fe3C nanoparticles and their crystallinity. The obtained Fe3C/N–C hybrid nanofibers-based oxidase-like catalyst shows a good long-term stability and reusability. Thanks to the unique catalytic activity for oxidase mimicking, an efficient sensing platform to sensitively determine sulfite and l-cysteine with low detection limits of 24.9 and 23.0 nM (S/N = 3), respectively, as well as excellent selectivity and anti-interference ability has been developed. This work demonstrates a versatile approach to fabricate Fe3C/N–C hybrid nanofibers as enzyme mimics with perfect catalytic efficiency, affording a facile and sensitive colorimetric approach for potential applications in biosensing and other biotechnologies.
Polyvinyl alcohol (PVA)/polyoxotungstoeuropate composite fibres were successfully prepared by a facile method called the electrospinning technique. Scanning electron microscopy (SEM) analysis revealed the fibre morphology of the composite. Transmission electron microscopy (TEM) showed spherical nanoparticles of the polyoxotungstoeuropate component with an average particle size of several nanometres to tens of nanometres and good dispersion. The electrospinning process prevented the polyoxometalate (POM) turning to an inhomogeneous microphase and large aggregation, so it is an effective and facile method for avoiding the phase separation of POM in the polymer matrices. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–vis) spectra were used to characterize the structure of PVA/polyoxotungstoeuropate composite fibres. The fluorescence properties of the composite fibres were also investigated.
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