Zn–Co Bimetallic Zeolitic Imidazolate Frameworks as Nonenzymatic Electrochemical Glucose Sensors with Enhanced Sensitivity and Chemical Stability

The development of nonenzymatic glucose sensors with favorable electrocatalytic activity and chemical stability is crucial in various fields. Therefore, in this study, we systematically investigate a series of ZIF-ZnxCo1–x materials (0 ≤ x ≤ 1) and demonstrate that the appropriate combination of Zn2+ and Co2+ within a metal–organic framework (MOF) delivers a promising platform for developing a glucose sensor with good glucose sensitivity and superior chemical stability. Herein, ZIF-Zn0.5Co0.5 was selected as the optimal glucose-sensing material owing to its high Co2+ content and well-preserved crystallinity and porosity after base treatment for 14 days. Remarkably, ZIF-Zn0.5Co0.5 showed superior electrocatalytic glucose-sensing performance compared to ZIF-67(Co) owing to its excellent chemical stability. The observed glucose-sensing performance was comparable to those of benchmark cobalt-based electrocatalysts. Furthermore, ZIF-Zn0.5Co0.5 exhibited excellent selectivity for glucose over possible interfering species, as well as reusability and electrochemical stability, thereby suggesting its potential applicability for nonenzymatic glucose sensing.