Multifunctional triphenylbenzene-based polyimide covalent organic framework with absolute eclipsed stacking models for fluorescence detecting of Fe3+ and electrochemical detecting of Pb2+

As a new crystalline material, the morphology of covalent organic frameworks (COFs) greatly influences its properties and applications. In this article, triphenylbenzene-based COFs (PMDA-TAPB) fibers with absolute eclipsed (AA) stacking models were obtained through adjusting the acetic acid dosage. For their plentiful active sites and high surface area, the fluorescence and electrochemical sensing properties of PMDA-TAPB COF were developed and utilized in this research. Meanwhile, the absorption competition quenching (ACQ) mechanism caused by Fe3+ has been demonstrated based on experimental and theoretical calculations. The Boolean logic gates illustrated the logical relationship between the fluorescence nature of PMDA-TAPB and system factors. The PMDA-TAPB modified carbon paste electrode (CPE) revealed excellent electron migration and Pb2+ chelating ability, which revealed an excellent detection ability for Pb2+ by differential pulse anodic stripping voltammetry (DPASV). This work opened up new prospects for multifunctional utilization of PI-COFs.