Oxygen Vacancy-Engineered Porous Nicu MOF@LDHs for Highly Sensitive Electrochemical Glucose Sensing

Abstract

Metal-organic frameworks (MOFs) and layered double hydroxides (LDHs) have emerged as highly efficient platforms for electrochemical sensors due to their simplicity, rapid response, low cost, and elevated sensitivity. However, the underlying mechanism of their interaction in electrochemical sensors is still unclear. Herein, the porous composite of MOF-supported LDHs (NiCu MOF@LDHs) is successfully fabricated using a simple hydrothermal method. Interestingly, the integration of LDHs and MOFs synergistically enhanced the hierarchical structure of the composite, leading to an increased specific surface area and improved electrical conductivity. Thus, the NiCu MOF@LDHs/GCE presents excellent glucose sensing features, including a good linear range (4.9504–1.1701 mM and 1.1701–2.8248 mM), a low detection limit (1.4249 μM, S/N = 3). Specifically, the sensor exhibited enhanced sensitivities (1071.1 and 545.2 µA mM^–1 cm^–2) and high selectivity in the presence of common interfering species including dopamine, hydrogen peroxide, ascorbic acid, L-arginine, and sodium chloride. Furthermore, the NiCu MOF@LDHs/GCE sensor demonstrated excellent performance in the practical detection of glucose levels in human serum, appreciating its potential for real-time applications. This work not only highlights the unique structural and functional properties of the NiCu MOF@LDHs composite but also paves the way for its future applications in glucose sensing and electrochemical biosensing.