Highly sensitive nonenzymetic glucose sensing platform based on MOF-derived NiCo LDH nanosheets/graphene nanoribbons composite

Herein, a novel sensing platform based on NiCo layered double hydroxide (LDH) nanosheets/graphene nanoribbons (GNRs) modified glassy carbon electrode is presented for sensitive non-enzymetic determination of glucose. In the first step, nanoflower-like NiCo LDH nanosheets were grown on the surface of ZIF-67 dodecahedron nanocrystals which used as sacrificial template and were further characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and FTIR. In the next step, in order to fabricate a mechanically stable modified electrode, the as-prepared nanosheets were mixed with narrow graphene nanoribbons synthesized through longitudinal unzipping of MWCNTs as an effective binder which in one hand increase the mechanical stability of the composite film and on the other hand, enhance the electrical conductivity of the final modified electrode. The catalytic behavior of the NiCo NSs/GNR modified electrode toward the electro-oxidation of glucose was investigated in NaOH alkaline solution by using cyclic voltammetry (CV) and amperometry techniques. As an enzymeless glucose sensor, the proposed sensing platform exhibited fast amperometric responses with high sensitivity (344μAmM−1cm−2) and low detection limit of 0.6μM within a wide dynamic linear range from 5μM to 0.8mM. Moreover, the electrode also demonstrated excellent selectivity toward glucose in the presence of common interfering species such as AA, DA and UA as well as good long-term stability which makes it an appropriate candidate for further practical applications. Schematic illustration of the GC electrode modification procedure with NiCo nanosheets/GNRs composite: (A) Synthesis of NiCo LDH NSs from ZIF-67 template, (B) preparation of narrow graphene nanoribbons via Longitudinal unzipping of MWCNT and (C) the electrode surface modification process by casting NiCo NSs/GNR suspension on the surafce of GCE. [Display omitted] •A novel sensing platform based on NiCo LDH nanosheets/graphene nanoribbons modified electrode is presented•Nanocrystals of ZIF-67 metal-organic framework is applied as the template for growing flower-like NiCo layered double Hydroxide•Narrow graphene nanoribbons synthesized via longitudinal unzipping of MWCNTs were used as an effective binder in electrode construction•The as-prepared modified electrode was examined as a nonenzymetic glucose sensing platform•The proposed