High-precision luminescent covalent organic frameworks with sp-carbon connection for visual detecting of nereistoxin-related insecticide

A new strategy for nereistoxin-related insecticide, cartap, detection in foodstuff and the environment is of great importance due to its poisoning of human beings through direct exposure or via biomagnification. Herein, a highly planar conjugated sp2 carbon-connected COF (F-Csp2-TT) was synthesized via Knoevenagel condensation reaction followed by the post-modification to develop a new platform for cartap visual detection in agricultural and food samples. The synergistic effect of highly planar conjugation and dense functional groups in the opened framework endowed F-Csp2-TT with a high-precision luminescence sensing performance. Meanwhile, the exquisitely designed F-Csp2-TT presented robust chemical stability, radiation stability, and good reproducibility. Benefiting from these advantages, high-precision luminescent F-Csp2-TT achieves a low detection limit of 0.51 μg/L to cartap over the range of 1-300 μg/L (R2=0.9938), and the recoveries percentage in food products was calculated as 95.90%- 119.3%. More significantly, the smartphone-based high-precision platform by F-Csp2-TT was established and successfully applied to portable monitoring of cartap and water content. Therefore, our work revealed the enormous potential of Csp2-connected COF, which opened a new situation for insecticide detection.