Cu,Zr-BTC/CNT composite for electrochemical detection of endocrine disruptor bisphenol A

Endocrine disruptors that may be present in plastic wastes can leach into surface water, pollute the environment and our drinking water; they must be monitored. In this study, an electrochemical sensor based on a metal organic framework (Cu, Zr-BTC) combined with carbon nanotubes (CNT) was developed for rapid on-site detection of bisphenol A—the most widely used monomer in plastics production. The Cu, Zr-BTC/CNT composite was first prepared by a solvothermal process in DMF solvent at 100 °C. For the first time, the Zr-based MOF with high proton conductivity was combined with Cu-based MOF with large active area in the same framework to provide an efficient platform for electrochemical detection. Morphological and structural studies revealed the coordination of Cu 2+ and Zr 4+ ions with organic ligands in a highly porous framework (active surface area up to 673 m 2 g −1 ). The use of highly conductive carbon nanotube material is to improve the recorded electrochemical signals. The developed bisphenol A sensor showed a linear response for bisphenol A concentrations from 2 to 50 µM, with a detection limit down to 0.5 µM and a sensitivity of 0.45 µA.µM −1 cm −2 . The sensors produced gave reproducible results (relative standard deviation of less than 7%) and were stable (relative standard deviation less than 12% after several days of storage). Tests on real samples were performed on Hanoi tap water and showed a satisfactory recovery (92–95%). The results were validated using high performance liquid chromatography. These results demonstrate the possibility of using such MOF materials in sensor applications. Graphical abstract