Development of a Highly Stable and Selective Non-Enzymatic Electrochemical Glucose Sensor Using Nitrogen-Doped Graphene Nanoribbons/NiCu-Metal-Organic Frameworks Composite

Bimetallic metal-organic frameworks (MOFs) show promise for electrochemical applications despite challenges posed by their low electrical conductivity and stability. Here, we introduce bimetallic (NiCu)-MOFs anchored on nitrogen-doped graphene nanoribbons (NGNRs) to enhance conductivity and stability. Experimental investigations on a (NiCu)-MOFs/NGNRs-modified glassy carbon electrode revealed a maximum oxidation current of 148 μA and a minimum charge transfer resistance of 4.01 kΩ, indicating excellent electrocatalytic activity. We further evaluated the modified electrode’s performance for glucose sensing using cyclic voltammetry and chronoamperometry techniques, achieving a notable oxidation peak current of 519 μA, which confirms its superior electrochemical activity. The developed enzyme-free glucose sensor exhibits a wide dynamic range (1.16 μM – 4.5 mM), high sensitivity (181.67 μA mM<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup>), short response time (3 s), and low detection limit (825 nM). Moreover, the proposed sensor exhibits better long-term stability, with a 96% amperometric response after seven days, and excellent selectivity in the presence of other interferents, such as ascorbic acid, dopamine, uric acid, and sucrose. This demonstrates its efficacy in human serum and non-alcoholic beverages.