Metal-organic frameworks based on functionalized polydentate heteroatom linkers integrated by graphitic carbon nitride nanosheets on epoxy–graphite electrodes: Application in electrocatalytic determination of propranolol

Functionalization of compounds is one of the most effective methods for creating new compounds with new properties and characteristics. Therefore, in this present study, multi-component nitrogen-containing compounds were utilized due to their high chemical reactivity and significant potential for structural modification. Accordingly, aliphatic and aromatic compounds incorporating oxygen and nitrogen atoms were selected as the most suitable candidates for achieving the objectives of this research. Therefore, in the first step, the 2,2′-benzimidazole compound was synthesized and subsequently functionalized with a halo-carboxylic acid derivative to form polydentate heteroatom linkers. The resulting MOFs composite were obtained through the coordination reaction between Cu (II) ions and the 2,2′-bibenzimidazole-dicarboxylic acid (BIMCA) ligand and g-C₃N₄ (GCN) on epoxy resin/graphite electrode (CEGEs) with Layer-by-Layer method (LbL) chemical nucleation methods. The synthesized compounds were characterized using FT-IR, 1 H NMR, XRD, SEM, EDX, and melting point technique. The practical application of Cu-MOFs/GCN/CEGES and the electrochemical behavior of Propranolol (PROP) were examined in PBS medium through various electrochemical techniques, such as differential pulse voltammetry (DPV), chronoamperometry (CHA), and cyclic voltammetry (CV). The essential parameters, such as the charge-transfer coefficient (α = 0.65), diffusion coefficient (D = 7.64 × 10 −4 cm 2 /s) and catalytic rate constant (K cat = 0.183 × 10 4 cm 3 .mol −1 . s −1 ), were evaluated for the electrocatalytic oxidation of PROP. The experimental findings show that the modified electrode successfully detects PROP through DPV, with a detection limit reaching 2.54 μM. Finally, the proposed electro-chemical sensing platform was successfully applied to determine low PROP concentrations in blood samples, suggesting its great applicability in clinical analysis and quality control. • New Cu-based MOF (Cu-MOFs) was prepared using a functionalized polydentate ligand. • A modified electrode (Cu-MOFs/GCN/CEGES) excellent electrocatalytic performance toward propranolol (PROP) oxidation. • The proposed electrochemical sensor showed an extended linear range and lower detection limits. • Low cost, simple drug sensor with good stability, repeatability and reproducibility.