Signal synergistic amplification strategy based on functionalized CeMOFs for highly sensitive electrochemical detection of phenolic isomers

A novel functionalized metal-organic frameworks (MOFs) was synthesized by decorating gold nanoparticles (AuNPs), electrochemical-reduced graphene oxide (ERGO) and carbon nanotubes (CNTs) on CeMOFs. As an ultra-sensitive electrochemical sensing platform, it was first applied to detect phenolic isomers (catechol (CC) and hydroquinone (HQ)) simultaneously through the signal synergistic amplification strategy. The performance of the electrochemical sensor has been significantly enhanced by the signal synergy based on the ordered pore nano-restriction effect of MOFs, the good stability and high conductivity of AuNPs and the ultra-fast electron migration rate produced by ERGO/CNTs with three-dimensional (3D) network structure. The sensor exhibits wide linear ranges of 3-190 mu M and 3-200 mu M with low detection limits of 0.73 mu M and 0.44 mu M for CC and HQ, respectively. Impressively, the sensor possesses ultra-stability, good repeatability and superior anti-interferent ability due to the stable porous 3D structure of the MOFs nanocomposites. It has been successfully applied to the detection of phenolic isomers in real samples with the recoveries of 100.1%-104.5% for CC and 93.5%104.0% for HQ. Therefore, the ERGO/CNTs/AuNPs@CeMOFs nanocomposites proved to be a very promising and highly sensitive sensing platform for phenolic isomers detection.