Enhanced non-enzymatic electrochemical glucose sensing through synergistic effect of Fe-based metal-organic framework and copper decorated carbon nanotubes

Metal–organic frameworks (MOFs) have attracted increasing attention in non-enzymatic glucose sensing. However, their non-conductive nature limits substantially their practical application. This study investigates a novel method to enhance glucose sensing capabilities by combining iron-based MOF (Fe-MIL-88B-NH₂) with copper nanoparticle decorated carbon nanotubes (Cu-CNTs) in a synergistic manner. The hydrothermaly synthesed, Fe-MIL-88B-NH₂ was coupled to Cu-CNTs using conductive polyvinylpyrrolidone polymer chains to get the Fe-MIL-88B-NH₂/Cu-CNT composite, which was immobilized on a nickel foam. All the materials were characterized by using Scanning Electron Microscopy, X-ray Diffraction, and Fourier Transform Infrared Spectroscopy. The designed Fe-MIL-88B-NH₂/Cu-CNTs composite based sensor demonstrated excellent performance, with a linear concentration range of 0.3 μM to 1 mM, a response time of 5 s, and a detection limit of 0.3 μM (S/N = 3) and sensitivity of 1.9 μAμM⁻¹cm⁻². Furthermore, the sensor was selective for glucose detection in the presence of typical biological interferents including uric acid, ascorbic acid, and dopamine.