Enhanced non-enzymatic glucose sensing based on porous ZIF-67 hollow nanoprisms

Abstract

Metal–organic frameworks (MOFs) as porous materials have significantly improved catalytic properties because of their rich active sites and large surface area. Herein, we develop a facile and efficient diffusion-controlled strategy to prepare ZIF-67 hollow nanoprisms (ZIF-67 HNPs) for a non-enzymatic glucose sensor. The interparticle pores of the hollow structure can afford fast diffusion pathway for guest molecules to move in and out of the MOF crystals. Such nanostructured MOF-based sensors exhibit good electrocatalytic activity towards glucose oxidation in an alkaline solution with a high sensitivity of 445.7 μA mM⁻¹ cm⁻², a low detection limit of 0.96 μM (S/N = 3) and a upper limit of 42.1 mM, and can be used to directly determine blood glucose. Moreover, it achieves well-pleasing results in the non-enzymatic analysis of glucose in real human blood serum samples. In addition, the as-prepared sensor also displays satisfactory reproducibility, selectivity and long-term storage stability. This study focuses on a facile strategy to design the in situ growth of hollow MOF nanomaterials as efficient and stable electrocatalysts, shedding light on the development of non-enzymatic sensors for monitoring glucose with transition metal-based hollow MOF catalysts.