A chemically and electrochemically stable, redox-active and highly sensitive metal azolate framework for non-enzymatic electrochemical detection of glucose

Abstract Herein, we demonstrated the development of a non-enzymatic glucose sensor based on a metal azolate framework (MAF-4-Co II or Co(mim) 2 , mim = 2-methylimidazole)-modified glassy carbon electrode (GCE). The as-synthesized MAF-4-Co II exhibited high crystallinity, purity, and chemical and electrochemical stability, which was characterized by various analytical methods. The MAF-4-Co II exhibited good redox activity in the alkaline medium due to the formation of MAF-4-Co II /MAF-4-Co III redox pair, which concurrently induced the non-enzymatic oxidation of glucose to gluconolactone. The MAF-4-Co II /GCE sensor exhibited wide dynamic ranges in the concentration range from 2 to 50 μM and 100 to 1800 μM with high sensitivity (ca. 990.90 and 30.95 μA/cm 2 /mM, respectively), low detection limit (ca. 0.60 μM), reproducibility, and selectivity. The practical applicability of this sensor was evaluated using diluted human serum samples, which revealed excellent recoveries of glucose. Thus, MAF-4-Co II can be used as a promising electrocatalyst for non-enzymatic detection of glucose with high stability.