Fabrication of a sensitive and fast response electrochemical glucose sensing platform based on co-based metal-organic frameworks obtained from rapid in situ conversion of electrodeposited cobalt hydroxide intermediates.

In this study, for the first time, we reported a fast and facile three-step in situ strategy for direct controllable growth of the Co3(BTC)2 MOFs thin films on the GCE, through the rapid conversion of the electrodeposited Co(OH)2 nano-flakes on rGO/GCE, to crystalline rectangular bar-shape structures of MOFs. X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and elemental mapping analysis used to the structural and morphological characterization of the well-synthesized MOFs. The as-prepared Co3(BTC)2 MOFs were used to construct a non-enzymatic sensing platform for determining the glucose in alkaline solution. The designed electrode demonstrated two wide linear dynamic range of 1 μM - 0.33 mM and 0.33 mM-1.38 mM with high sensitivity of 1792 μA mM-1 cm-2 and 1002 μA mM-1 cm-2, respectively, good repeatability and reproducibility, high selectivity against interference species and good poisoning resistance against chloride ions and a low detection limit of 0.33 μM (S/N = 3). Finally, the application of the proposed sensor for the determination of glucose in the human blood serum samples was investigated and results showed excellent recoveries, which confirmed that the fabricated sensor can act as a reliable and sensitive platform for biological and clinical samples analysis.