AgNO3-anchored Prussian blue-derived porous Ag/α-Fe2O3 heterostructure with enhanced electrochemical sensing performance towards methylparaben

Herein, we report on facile fabricating sensors based on Ag/α-Fe₂O₃ nanocubes harvesting by one-step pyrolyzing Prussian blue (PSB) template anchored AgNO₃ at different temperatures (300~500°C) and exploiting them for electrochemical sensing of methylparaben (MP). The Ag/Fe₂O₃ nanocubes had crystallite sizes ranging from 300~400 nm and incorporated reduced Ag nanoparticles (AgNPs) ranging from 10.5~15.3 nm. Notably, the harvested Ag/Fe₂O₃ composites were constructed hetero-interfacial Ag–Fe₂O₃ structures inside the porous α-Fe₂O₃ cubes with interconnected pore matrix resulting from the thermal conversion of PSB. The carbon glass electrode (GCE) coated with an Ag/Fe₂O₃ sensor prepared at 400°C showed the highest oxidation peak at 0.84 V towards MP. In addition, the Ag/α-Fe₂O₃@GCE interface achieved an excellent detection of MP with a low LOD of 0.14 µM and a linear response range of 10~38 µM. The sensor also depicted good selectivity and stability during 10 days, demonstrating a suitable sensor for detecting and analyzing MP. This study provides a facile strategy for constructing a porous Ag/Fe₂O₃ heterostructural composite as an efficient electrochemical sensing material.

Graphical abstract

Sensors based on Ag/α-Fe₂O₃ nanocube harvesting by one-step pyrolyzing Prussian blue (PSB) template anchored AgNO₃ and exploited for the electrochemical sensing of methylparaben. The results suggest that Ag/α-Fe₂O₃ nanocube crystals comprise heterointerfaces and interconnected pores. The Ag/α-Fe₂O₃@GCE interface exhibited excellent detection of methylparaben, good stability, and selectivity.