Cathodic electrodeposited Cu-BTC MOFs assembled from Cu(II) and trimesic acid for electrochemical determination of bisphenol A

The authors describe a novel electrochemical determination method for bisphenol A (BPA) based on the electrosynthesised Cu-BTC (H₃BTC: trimesic acid) films. Using H₃BTC as the ligand, Cu(NO₃)₂ as the precursor of copper ions, and triethylamine hydrochloride (Et₃NHCl) as the probase source, Cu-BTC films were directly deposited on glassy carbon electrode (GCE) surface via cathodic electrochemical reduction under −1.30 V. Considering the electrocatalytic activity of metal center Cu²⁺, Cu-BTC films were applied to construct the electrochemical determination platform for BPA. Chronocoulometry and electrochemical impedance spectroscopy were used to study the signal enhancement mechanism. The determination conditions were optimized. As a result, a sensitive electrochemical method was constructed for BPA. The peak currents, best measured at voltage of 0.496 V vs. SCE (KCl saturated calomel reference electrode), increase linearly in the range from 5.0 to 2000 nM. The value of determination limit is 0.72 nM. The proposed method was successfully applied to determine BPA in spiked urine, spiked waste water samples and plastic products. The results were in good agreement with those obtained for the same samples by high-performance liquid chromatography (HPLC).