A single N-rich covalent organic framework-based sensor for electrochemical sensing of 2,4,6-trichlorophenol

2,4,6-trichlorophenol (TCP), a widely used pesticide ingredient, poses the hazardous harm to the surrounding environment and human health due to its persistence and toxicity. In this work, a single free-metal nitrogen-rich (N-rich) covalent organic framework (COF), denoted as COF_PD-TAPT, was synthesized and then assembled with the glass carbon electrode (GCE) to fabricate a COF_PD-TAPT/GCE sensor. Benefiting from its porous structure, large electrochemical surface area and abundant nitrogen-containing active sites, thus, the prepared COF_PD-TAPT/GCE sensor demonstrated excellent performance towards the oxidation of TCP with the wide linear range and an outstanding limit of detection. Furthermore, the fabricated COF_PD-TAPT/GCE sensor demonstrated satisfactory recoveries in real samples of tap water, tomato juice and apple juice, which were also certified by HPLC measurements. This work highlights the huge potential of single COF in advancing electrochemical sensing filed.