Polyhedral NiO/C porous composites derived by controlled pyrolysis of Ni-MOF for highly efficient non-enzymatic glucose detection

Polyhedral NiO/carbon porous composites with highly dispersed NiO nanoparticles were successfully obtained by controlled pyrolyzing Ni-MOF precursors. The effect of the pyrolysis temperature on morphology, crystal structure and glucose-sensing performance of the composite materials was investigated in detail. The kinetic analysis demonstrated high electrocatalytic activity (K_cat, 2.09 × 10⁶ M⁻¹ s⁻¹) for glucose oxidation on the obtained electrode materials. The constructed Ni-MOF400 sensors displayed ultra-high sensitivity (2918.2 μA mM⁻¹ cm⁻²) for non-enzymatic glucose sensing with a relatively wide detection linear range (5 μM–4.1 mM) and low detection limit (0.92 μM). The high glucose sensing performance may be due to the greatly reduced charge transfer resistance (0.412 kΩ for Ni-MOF400 vs 19.27 kΩ for Ni-MOF800) originating from the synergistic effect of highly dispersed NiO nanoparticles and porous carbons. Moreover, the sensors also presented good selectivity in the presence of various interferents (l-lysine, urea, l-leucine, ascorbic acid, l-valine, NaCl, l-glutamic, and l-proline). The reasonable analytical recovery ranging from 103 to 108.1% for the glucose detection in bovine serum was also obtained, suggesting the preferable feasibility of the Ni-MOF400 sensors for the real sample analysis.