2D EC-MOF nanowire arrays for highly sensitive electrochemical detection of trace paraquat

Paraquat (PQ) is a highly toxic herbicide but widely used in agricultural production. Highly sensitive detection of trace PQ is vital and challenging. Herein, two-dimensional electronically conductive metal–organic framework (2D EC-MOF) Ni 3 (HHTP) 2 (HHTP: 2,3,6,7,10,11-hexahydroxytriphenylene) is in situ constructed on the carbon paper and employed as an electrochemical sensor for PQ detection for the first time. The Ni 3 (HHTP) 2 electrochemical sensor exhibits a high detection sensitivity (175 μA·μM −1 ·cm −2 ), low detection limit (4.4 nM), good reproducibility, and strong anti-interference ability. In addition, the sensor shows reliable performance in the detection of PQ in real samples including apples, cucumbers, tomatoes, and pears (detection recovery is 95.4–104.4%). Furthermore, zeta potential test (a method which can obtain zeta potential value on the particle surface) and density functional theory (DFT) calculation confirm that the strong electrostatic interactions between active sites and PQ are conducive to the high-sensitivity detection of PQ. The accession of 2D EC-MOF to PQ electrochemical sensor provides new ideas for sensor design and broadens the scope of EC-MOF’s applications. Graphical abstract