The porous hollow cobalt-based oxides encapsulated with bimetallic PdAu Nanoparticles of electrochemical biosensor for highly sensitive pesticides detection

Abstract Efficient and portable electrochemical biosensors are received to evaluation of pesticides in the environment, which can make great significance for food safety. In this study, the Co-based oxides with a kind of hierarchical porous hollow and nanocages were constructed, in which the materials (Co 3 O 4 -NC) were encapsulated with PdAu nanoparticles (NPs). Due to the unique porous structure, the changeable valence state of cobalt and the synergistic effect of bimetallic PdAuNPs, PdAu@Co 3 O 4 -NC possessed excellent electron pathways, and showed more exposed active sites. Accordingly, the porous Co-based oxides have been applied to construct an acetylcholinesterase (AChE) electrochemical biosensor, which showed good performance for organophosphorus pesticides (OPs) detection. The optimum biosensing platform based on nanocomposites was applied to exhibit highly sensitive determination of omethoate and chlorpyrifos, with the relative low detection limit of 6.125 × 10 −15 M and 5.10 × 10 −13 M, respectively. And a wide detection range of 6.125 × 10 −15 ∼ 6.125 × 10 −6 M and 5.10 × 10 −13 ∼ 5.10 × 10 −6 M for these two pesticides were achieved. Therefore, the PdAu@Co 3 O 4 -NC may represent a powerful tool for ultrasensitive sensing of OPs, and have great potential application.