Molecularly imprinted electrochemical sensor based on copper 4-amino benzoic acid metal-organic framework for determination of pregabalin: electrochemical and DFT studies

This study introduces a novel detection approach for determining trace levels of pregabalin (PGB), which utilizes the combination of two advanced metal-organic frameworks (MOFs) with a molecularly imprinted polymer (MIP) technique. For this purpose, we have developed a highly sensitive electrochemical sensor for measuring and determining PGB. The first step involved modifying a carbon paste electrode (CPE) with a Cu-MOF. PGB was employed as a template in the electropolymerization of poly-orthophenylenediamine (POPD) by cyclic voltammetry. The sensors' electrochemical performance was evaluated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The results obtained from the DPV revealed three linear response ranges of 0.003-0.09 µM,0.1-1 µM, and 1-90 µM with a low detection limit of 1.2 nM (signal-to-noise ratio = 3) and sensitivity 17.20 µA/µM. Moreover, the built-in sensor was utilized to measure PGB levels in both blood and Tablet with recoveries ranging from 96.67 to 109.19%. A detailed analysis of molecular structures, binding energies, and binding thermodynamic parameters of PGB-POPD configurations was performed using density functional theory methods. The calculated standard enthalpy change of binding indicates an exothermic process for all dimer and trimer configurations.