Design and development of Co-MOF as an efficient electrochemical platform for H2O2 sensing

Abstract

Hydrogen peroxide (H₂O₂) detection is crucial in biological, environmental, and industrial contexts, serving as a biomarker for oxidative stress, an enzymatic reaction product, and a common oxidizing agent. Metal–organic frameworks (MOFs) have emerged as promising candidates for electrochemical sensors due to their unique structural properties and tunable characteristics. This study reports the synthesis and characterization of a cobalt metal–organic framework (Co-MOF) as an electrochemical platform for H₂O₂ detection. The Co-MOF was synthesized via a two-step procedure: formation of the organic ligand (H₂L) followed by coordination with cobalt centers. Electrochemical characterization revealed excellent electron transfer properties with a surface-controlled process (b = 0.992) and diffusion-controlled kinetics. The sensor exhibited a high sensitivity of 91.75 μA/μM/cm² towards H₂O₂, with a linear response range of 2–1000 μM and a detection limit of 0.25 μM (S/N = 3). The enhanced sensing performance can be attributed to synergistic mechanisms: rapid electron transfer via Co centers, facilitated mass transport through the porous structure, and efficient catalytic decomposition of H₂O₂. Electrochemical impedance spectroscopy indicated a low charge transfer resistance (~ 200 Ω), suggesting favorable interfacial properties. This study establishes a foundation for developing high-performance MOF-based electrochemical sensors for H₂O₂ detection in biological and environmental applications, with potential utility in clinical diagnostics, environmental monitoring, and industrial process control.