Heavy metal ion (HMI) pollution is a serious threat to human health and the ecosystem. Therefore, there is an urgent need to develop a fast and sensitive platform for heavy metal ion detection. In this work, a novel sensing platform based on ZIF-67-derived cobalt/nitrogen-doped carbon (NC) composite polyhedrons linked with multiwalled carbon nanotubes (MWCNTs), termed Co@NC/MWCNT, for the simultaneous monitoring of Cd2+ and Pb2+ was established. In detail, nanoporous ZIF-67 was first in situ grown on the MWCNTs, followed by carbonization, endowing the composite with good electrical conductivity and a large specific surface area, providing more active sites for subsequent metal ion attachment. Under optimal parameters, the proposed sensing platform exhibited a relatively wider linear range of 0.12–2.5 μM, with lower limits of detection (LODs) of 4.5 nM (Cd2+) and 4.9 nM (Pb2+). Notably, it was worth mentioning that the linearity of the as-prepared sensing platform in the actual water sample was highly consistent with the linearity in the buffer solution, showing outstanding anti-interference performance. Finally, the designed sensing platform performed well in several kinds of natural water environment when compared with the standard method, demonstrating huge potential in trace HMI monitoring.

No abstract

Herein, a gold nanoparticles/graphene aerogel (AuNPs/GAs) modified electrochemical biosensor compounded with catalytic hairpin assembly (CHA) and Y-shaped DNA nanostructure dual signal amplification approaches for the ultrasensitive microRNA-21 (miR-21) detection was...

No abstract