Ti3C2-MXene@N-doped carbon heterostructure-based electrochemical sensor for simultaneous detection of heavy metals

•This study proposes a new strategy for improving the electrochemical characteristics of Ti3C2-MXene by using heterostructure and nitrogen-doping effect, and develops a highly sensitive sensor for selective and simultaneous determination of HMIs.•The promoted interface charge transfer by heterojunction structure combines with the coordination by nitrogen, improving the metals determination performance.•The effect of nitrogen on Cd2+ or Pb2+ was interpreted by adsorption tests and XPS.•The sensing mechanism of the detection by Ti3C2@N-C modified on the electrode surface is exhibited.