Facile design and synthesis of ultrafine FeCo nanocrystallines coupled with porous carbon nanosheets as high efficiency non-enzymatic glucose sensor

Abstract

A series of FeCo alloy nanoparticles coupled with porous carbon nanosheets (denoted as FeCo@PCNSs-T) are successfully synthesized by calcining the three dimensional (3D) porous precursor networks (prepared by electrospinning technique) at different pyrolysis temperatures. The glucose oxidation and detection performances of the resultant FeCo@PCNSs-T catalysts decrease in the order of FeCo@PCNSs-800 > FeCo@PCNSs-700 > FeCo@PCNSs-900 > FeCo@PCNSs-1000 > FeCo@PCNSs-600. The experimental results prove that the optimal FeCo@PCNSs-800 catalyst exhibits a rapid response time (3.0 s), large sensitivity values (1766.5 μA cm−2 mM−1 between 0.005 and 1.70 mM and 826.7 μA cm−2 mM−1 between 1.70 and 13.60 mM), a low detection limit (0.1 μM), excellent anti-interference to electroactive molecules and Cl−, a perfect reproducibility and a superior long-term stability for glucose sensor. The structural and chemical components of the resultant FeCo@PCNSs-T catalysts are analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, N2 adsorption–desorptionand X-ray photoelectron diffraction techniques. On the basis of the resultant experimental results, we can confirm the major factors of an excellent glucose sensor efficiency of the FeCo@PCNSs-800: (1) the FeCo alloy nanoparticles coupled with PCNSs can enhance the conductivity of composite. (2) The Fe elements in FeCo alloy nanoparticles can increase the number of active CoIV sites. (3) The 3D hierarchically porous architectures afford a large surface area for dispersing more ultrafine FeCo nanoparticles, which can obviously increase the number of CoIV sites. (4) The meso/macroporous channels can effectively decrease the mass transport resistances. Furthermore, the FeCo@PCNSs-800 catalyst also exhibits a satisfying efficiency for glucose detection in human serum samples.