High-performance non-enzymatic glucose sensor by hierarchical flower-like nickel(II)-based MOF/carbon nanotubes composite.

A hierarchical three-dimensional flower-like nickel(II)-terephthalic acid (Ni(TPA)) metal-organic framework (MOF) was synthesized through a simple solvothermal method. Then the single-walled carbon nanotubes (SWCNT) were doped with the synthesized Ni(TPA) MOF by the ultrasonic method to improve the chemical stability and the electrochemical activity of the MOF. To explore the potential application of the nanocomposite, the Ni(TPA)-SWCNT modified glassy carbon electrode was prepared and used as a non-enzymatic electrochemical sensor for glucose. The results show that the nanocomposite demonstrates remarkably higher electrochemical response as well as stronger electrocatalytic activity toward glucose oxidation, in comparison with the single-component of Ni(TPA) and SWCNT. The Ni(TPA)-SWCNT modified electrode exhibits outstanding performance including excellent selectivity, wide linear range from 20 μM to 4.4 mM, low detection limit of 4.6 μM, and fast response (<5 s) for glucose detection. For glucose analysis in real serum samples, the developed sensor reveals a good agreement with the automatic biochemical analyzer, with the deviation rate of 0-6.7% and correlation coefficient (r) of 0.9940 (n = 20, P < 0.0001), indicating high accuracy and great potential of the sensor for practical application in fast analysis of glucose.