Development of a ZIF-8/LIG-based electrochemical biosensor for accurate and reliable glucose monitoring in blood.

Harnessing the exceptional enzyme immobilization capabilities of metal-organic frameworks (MOFs) and the exceptional electrochemical characteristics of graphene, we designed a highly efficient and cost-effective glucose sensor utilizing zeolitic imidazolate framework-8 (ZIF-8) and laser-induced graphene (LIG) with the aid of mediator ferrocene (Fc). By incorporating a cellulose acetate (CA) film as an anti-interference layer and a polyurethane (PU) film as a diffusion-limiting layer, the sensor exhibited a wide linear detection range for glucose (0.62 mM to 20 mM) with a low detection limit of 0.16 mM (S/N = 3). Notably, it demonstrated excellent selectivity, with no interference from common biological substances. The sensor also exhibited good stability, retaining 96.38% of its initial performance after 7 days of storage. Additionally, the sensor was effectively utilized for glucose detection in whole blood, with results closely matching those obtained from a commercial blood gas analyzer (GEM5000), as evidenced by a high Pearson's correlation coefficient (r = 0.9974). This method provides a portable glucose sensor that produces results highly consistent with those obtained from large-scale testing devices in hospitals, enabling convenient and accurate blood glucose monitoring for patients.