Post-modification of covalent organic framework functionalized aminated carbon nanotubes with active site (Fe) for the sensitive detection of luteolin.

In this research, the TT-COF(Fe)@NH 2 -CNTs was innovatively prepared through a post-modification synthetic process functionalized TT-COF@NH 2 -CNTs with active site (Fe), where TT-COF@NH 2 -CNTs was prepared via a one-pot strategy using 5,10,15,20-tetrakis (para-aminophenyl) porphyrin (TTAP), 2,3,6,7-tetra (4-formylphenyl) tetrathiafulvalene (TTF) and aminated carbon nanotubes (NH 2 -CNTs) as raw materials. The complex TT-COF(Fe)@NH 2 -CNTs material possessed porous structures, outstanding conductivity and rich catalytic sites. Thus, it can be adopted to construct electrochemical sensor with glassy carbon electrode (GCE). The TT-COF(Fe)@NH 2 -CNTs/GCE can selectively detect luteolin (Lu) with a wide linear plot ranging from 0.005 to 3 μM and a low limit of detection (LOD) of 1.45 nM (S/N = 3). The Lu residues in carrot samples were determined using TT-COF(Fe)@NH 2 -CNTs sensor and UV–visible (UV–Vis) approach. This TT-COF(Fe)@NH 2 -CNTs/GCE sensor paves the way for the quantification of Lu through a cost-efficient and sensitive electrochemical approach, which can make a significant step in the sensing field based on crystalline COFs. • The TT-COF(Fe)@NH 2 -CNTs was designed and synthesized with high conductivity and activity. • TT-COF(Fe)@NH 2 -CNT represents the first example with Fe N 4 active sites for detecting luteolin. • The developed sensor was successfully applied for the analysis of luteolin in carrot samples. [ABSTRACT FROM AUTHOR]