A micromilled microgrid sensor with delaminated MXene-bismuth nanocomposite assembly for simultaneous electrochemical detection of lead(II), cadmium(II) and zinc(II)

A delaminated MXene-bismuth (Bi@d-Ti3C2) nanocomposite was synthesized for the construction of a microgrid electrochemical sensor via mechanical milling. The Bi@d-Ti3C2 nanocomposite was synthesized by accumulation of Bi(III) on the surface of delaminated Ti3C2 nanosheets through electrostatic attraction and subsequent in-situ growth of bismuth nanorods. Under optimized experimental conditions, the sensor exhibits (a) linear responses to Pb(II), Cd(II) and Zn(II) in the concentration range from 1 to 20 μg L−1, (b) well separated peak potentials at −0.54 V, −0.76 V and − 1.15 V vs. Ag/AgCl, (c) sensitivities of 0.98, 0.84 and 0.60 μA L μg−1, and (d) detection limits of 0.2, 0.4 and 0.5 μg L−1, respectively. This performance is attributed to the uniform dispersion of Bi nanorods on electrically conductive delaminated Ti3C2 MXene, and to the enhanced diffusion due to the microgrid structure.