Electrochmical Sensing Platform for Detection of Lead(II) and Cadmium(II) Based on Mixed-Aerogels Loaded with Bismuth Nanoparticles

Heavy metals have the characteristics of low concentration, high toxicity and biological undegradability. The heavy metal ion pollution of environmenial water systems pose a great threat to human health. In this work, carboxy carbon nanotubes (MWCNT-COOH) and dialyzed graphene oxide (GO) were bonded to form a 3D mixed-aerogels (MAs) of hierarchical porous structure with polydopamine (PDA) as the `cross-linking agent , similar to cabbage-like. Bismuth nanoparticles ( BiNPs) were loaded in situ on MAs as the substrate to construct an electrochemical sensor. Differential pulse stripping voltammetry (DPSV) was used to detect Pb2+ and Cd2+ simultaneously. The linear ranges were 5-500 ng/L and 0. 5-70 mu g/L, and the corresponding detection limits (S/N= 3) were 0. 13 ng/L and 0.49 ng/L for Pb2+ and Cd2+ , respectively. The experimental results showed that the sensor had high accuracy, high stability and anti-interference properties. The sensor was expected to be of great significance for simultaneous detection of heavy metals.

Automated summary

Heavy metal pollution in environmental water systems poses a great threat to human health. In this study, a 3D mixed-aerogels with hierarchical porous structure was successfully synthesized by bonding carboxy carbon nanotubes and dialyzed graphene oxide, with polydopamine as the cross-linking agent. Bismuth nanoparticles were loaded in situ as the substrate to construct an electrochemical sensor for simultaneous detection of Pb2+ and Cd2+ with high accuracy and anti-interference properties.