Ultrathin nickel-metal–organic framework nanobelt based electrochemical sensor for the determination of urea in human body fluids

Ultrathin nickel-metal–organic framework (Ni-MOF) nanobelts, [Ni20(C5H6O4)20(H2O)8]·40H2O (Ni-MIL-77), have been exploited successfully for the fabrication of a non-enzymatic urea sensor. Ni-MOF ultrathin nanobelts in alkaline media can be used as an efficient catalyst for urea electrooxidation. As a non-enzymatic urea sensor, Ni-MOF ultrathin nanobelts exhibit a high sensitivity of 118.77 μA mM−1 cm−2, wide linear range of 0.01–7.0 mM, and low detection limit of 2.23 μM (S/N = 3). The selectivity, stability and reliability of ultrathin Ni-MOF nanobelts towards urea oxidation are also investigated. Moreover, Ni-MOF ultrathin nanobelts were further used to detect urea in human body fluids. All these findings confirm that the urea sensor based on Ni-MOF ultrathin nanobelts is successfully prepared and promising for applications in medical diagnostics and environmental monitoring.