Ionic Covalent Organosilicon Polymer Nanosheet for Selective and Sensitive Detection of Dopamine

Covalent organic polymer (COP) nanosheets are unique materials with broad applications in energy storage and conversion, chemical sensing, and gas storage. It remains challenging to develop an efficient method to fabricate COP nanosheets from designed monomers, especially for self-exfoliated COPs. Herein, we present a new strategy to prepare self-exfoliated COPs by reversible condensation of hexahydroxytriphenylene (HHTP) with phenyltrimethoxysilane. The prepared COP has a pentacoordinated silicon center and negatively charged surface, making it easily exfoliated to nanosheets with 1.07 nm thickness. Moreover, this COP could be used as a highly selective electrochemical sensor for dopamine (DA) in the range of 0.1–120 μM with a detection limit at 52 nM (S/N = 3). This study provides a new strategy for designing ionic COP nanosheets and expands the application of ionic COP for electrochemical sensing.