A simple one-pot approach to prepare composites based on bimetallic metal–organic frameworks M, Ni-BTC (M = Cu, Fe) and carbon nanotubes for electrochemical detection of bisphenol A

Metal–organic frameworks (MOFs) with large active surface area have recently gained considerable attention due to their potential applications in electrochemical sensing. In this work, composites based on carbon nanotubes and bimetallic metal–organic frameworks are presented as the electrochemical platforms for the detection of emerging water contaminants, such as bisphenol A. The performance of the sensors was optimized and evaluated using differential pulse voltammetry technique. The results show an enhancement of the electrochemical output signals for the electrodes modified with Cu,Ni-BTC/CNT and Fe,Ni-BTC/CNT composites. The results have also demonstrated the important role of nickel ions which are indeed present in the samples at relatively low content (four times less than Cu and Fe ions). The detection limits of bisphenol A sensor based on Cu,Ni-BTC/CNT and Fe,Ni-BTC/CNT were 0.5 and 0.7 µM, respectively. In the same time, the morphological and structural studies have shown a better quality of crystals in Cu,Ni-BTC/CNT and a more porous structure in Fe,Ni-BTC/CNT; which might be responsible for the better sensing performances on the electrode modified with Cu,Ni-BTC/CNT. The proposed method is versatile and can be used to prepare a wide range of composites made of these bimetallic MOF structures with different additives, depending on the target applications.