Rational design of a mesoporous silica@ZIF-8 based molecularly imprinted electrochemical sensor with high sensitivity and selectivity for atropine monitoring

Porous materials are of great interest for sensor design, while poor conductivity and single structure hinder their electrochemical application seriously, and the development of an effective way to improve their specificity for targets is another challenge. Herein, novel flower-like core-shell mesoporous silica nanospheres@zeolitic imidazolate framework-8 (MSN@ZIF-8) hybrid electrocatalyst with hierarchical framework, enhanced porosity, tunable functionality, and excellent stability was firstly attempted. Significantly, the electronic environment and dynamics were greatly enhanced in MSN@ZIF-8, owing to the abundant faradic active sites of MSN inner cores and plentiful pores for electrolyte permeation and analytes adsorption of ZIF-8 outer shell. Thereafter, the molecularly imprinted electrochemical sensor based on MSN@ZIF-8 nanocomposites was prepared with p-aminothiophenol as functional monomer, Au nanoparticles as cross-linker, and atropine as template molecule via electropolymerization technique, which had a wide linear range, subnanomolar detection limit, and specific selectivity for atropine monitoring. Our work will inspire further studies on developing porous electrocatalysts with improved stability and performance, which is highly expected for varieties of sensor applications.

Automated summary

The study introduces a novel flower-like core-shell mesoporous silica nanospheres@zeolitic imidazolate framework-8 (MSN@ZIF-8) hybrid electrocatalyst with hierarchical framework, enhanced porosity, tunable functionality, and excellent stability. A molecularly imprinted electrochemical sensor based on MSN@ZIF-8 nanocomposites was developed with wide linear range, subnanomolar detection limit, and specific selectivity for atropine monitoring. Further research on porous electrocatalysts with improved stability and performance for various sensor applications is highly anticipated.