Hierarchical porous hollow N-doped Cu-based MOF derivatives as highly sensitive electrochemical sensing platform for pesticides detection

Pesticides have long posed serious threats to human health, and the development of efficient sensors for ultratrace pesticides detection is urgently needed. In this work, a class of hierarchical porous hollow N-doped Cu-based nanocages (HPH-N-Cu NCs) is reported as a highly sensitive electrochemical sensing platform for organophosphates pesticide detection. Due to their unique micro-/mesoporous structures, the changeable valence state of copper and heteroatom doping, HPH-N-Cu NCs show more exposed active sites, multiple reaction interfaces and enhanced conductivity, which result in high electrocatalytic ability toward the oxidation of electroactive products. Accordingly, the acetylcholinesterase (AChE) biosensor based on HPH-N-Cu NCs shows a smaller Michaelis-Menten constant of 126 μM for acetylthiocholine chloride, while achieving a low detection limit of 2.58 × 10−11 g/L (S/N = 3) and a wide detection range of 1.00 × 10−9 to 1.00 × 10−3 g/L for methamidophos. Moreover, the prepared biosensor exhibits good stability and high accuracy in real sample detection. The HPH-N-Cu NCs electrode materials may serve as promising tools for the sensitive monitoring of multiple pollutants. •Porous hollow nitrogen-doped copper-based electrode material was developed.•The electrode offers more exposed active sites and excellent catalytic ability.•The electrode material endows the biosensor a smaller Michaelis-Menten constant.•A low detection limit and a wide detection range for methamidophos determination are realized.