An ultra-sensitive electrochemical dopamine sensor based on Ni@N-doped carbon derived from COF LZU-1 microspheres

N-rich carbon (C) microspheres loaded with Ni nanoparticle (NiNP) microspheres (Ni@N-doped C) were obtained by calcination of covalent organic framework (COF) LZU-1 with abundant N atoms/Ni 2+ . Lots of NiNPs with the size of 4 nm are arrayed uniformly and firmly into N-doped C microspheres derived from COF LZU-1 based on the strong coordination between N atoms on the wall of well-ordered pores and Ni atoms, which is more beneficial to rapid electron and mass transfer. The synergistic effect from N-doped C microspheres and small-sized NiNPs in Ni@N-doped C enhances catalytic activity of Ni@N-doped C microspheres greatly, which provides feasibility for the construction of non-enzymatic electrochemical sensor. The non-enzymatic electrochemical sensor based on Ni@N-doped C microspheres is applied to the detection of dopamine (DA) and shows good detection results with a low detection limit of 0.009 μM and a wide detection range of 0.027–70 μM. What is more, this DA sensor has good anti-interference, reproducibility, and stability, which provides new idea for the construction of non-enzymatic electrochemical sensor.