In situ fabrication of cobalt nanoflowers on sulfonated and fluorinated poly (arylene ether ketone-benzimidazole) template film for the electrocatalytic oxidation of glucose

Using sulfonated and fluorinated poly (arylene ether ketone) comprising functional strong coordination group benzimidazole (SPAEK-F-BI) as a template film, a novel fabrication method of cobalt nanoflowers (CoNFs) and non-enzymatic glucose electrochemical sensor was developed in this work. After the precursors Co2+ ions were cooperatively bound by sulfonate and imidazole functionalities contained in SPAEK-F-BI film through ion exchange and strong coordination action, cobalt colloid nuclei were formed and grew to flower-like nanostructures by subsequent in-situ electrochemical reduction on SPAEK-F-BI film modified GCE. Characterization of SPAEK-F-BI film and CoNFs/SPAEK-F-BI film on GCE was performed in detail by FT-IR spectroscopy and scanning electron microscopy (SEM) attached with energy dispersive spectroscopy (EDS), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The results of SEM showed that beautiful CoNFs constructed by Co colloid nanosheets with just a few nanometers thickness were well dispersed on uniform SPAEK-F-BI film modified GCE, and the density of CoNFs was mainly influenced by the concentration of the precursor solution CoSO4. The CoNFs/SPAEK-F-BI composite modified electrode exhibited good electrocatalytic activity toward glucose oxidation in 0.1 M NaOH solution, and the kinetic parameters of glucose oxidation were determined using chronoamperometry. When it was applied for the determination of glucose by amperometry at a potential of 0.6 V versus Ag/AgCl, the linear range from 5 M to 1.14 mM and the detection limit of 800 nM (S/N = 3) were obtained. Finally, it was successfully employed to detect the glucose in human serum real samples, and the results were agreed closely with those measured in hospital.