Dispersed Au Nanoparticles Anchored on Covalent Organic Frameworks/Carbon Nanotubes via Self-Reduction for Electrochemical Sensing of Acetaminophen

In this study, the gold nanoparticles (AuNPs) supported by a covalent organic framework (COF) were designed and produced by a self-reduction method, which could effectively avoid the aggregation of AuNPs. The amino and aldehyde groups in the COF are crucial for the self-reduction of AuNPs. The porous COF with a high specific surface area not only serves as an anchoring platform for AuNPs but also enhances the adsorption abilities toward acetaminophen (AP). The AuNPs can facilitate the electron transfer capabilities of the catalyst and enhance the electrocatalytic activity of the catalyst. Due to the excellent electrical conductivity of carbon nanotubes, COF@AuNPs were composited with multi-walled carbon nanotubes (MWCNTs) by the ultrasound method. COF@AuNPs@MWCNTs were applied to build an electrochemical sensing platform to measure AP. The COF@AuNPs@MWCNTs/GCE displays a wide detection range for AP (0.1-500, 500-1200 μM) with a detection limit of 80 nM. The constructed electrochemical sensor can be utilized for the assay of AP in the actual sample serum with recoveries of 98.20-102.2%. Such a self-reducing synthesis method opens up perspectives for the design of COF@metal NPs for a broad range of applications such as sensing, energy, and catalysis.