Non-enzymatic electrochemical sensor for hydrogen peroxide detection using Nafion/copper-based metal-organic gel modified glassy carbon electrode

A highly sensitive and selective non-enzymatic electrochemical sensor for hydrogen peroxide (H 2 O 2 ) detection was developed based on a glassy carbon electrode modified with Nafion/copper-based metal-organic gels (NF/Cu-MOGs/GCE). The copper-based metal-organic gels featured a porous three-dimensional network hosting electroactive Cu(I)/Cu(II) redox pairs. The as-prepared NF/Cu-MOGs/GCE sensor exhibited good electrocatalytic activity toward the reduction of H 2 O 2 , achieving a wide linear range from 5 to 10,025 μM and a low detection limit of 0.28 μM (S/N = 3). The sensor also demonstrated high selectivity against common interferents, excellent reproducibility, and satisfactory stability. Its practical applicability was successfully validated by determining H 2 O 2 in milk samples, with recoveries ranging from 98.6% to 102.0%, which were in good agreement with values obtained using a reference colorimetric method. This work not only presents a robust sensing platform for H 2 O 2 monitoring, but also highlights the significant potential of MOGs as versatile functional materials in electrochemical sensing.