MnFe₂O₄-based hybrid nanomaterials for high-performance electrochemical sensors: recent progress and future...

Manganese ferrite (MnFe₂O₄) is a promising electrode material because of its redox-active Mn and Fe centers, chemical stability, and tunable spinel structure. However, its practical use in electrochemical sensing may be limited due to its poor electrical conductivity, particle aggregation, and limited access to active sites. This review discusses recent advances in the fabrication of pristine and hybrid MnFe₂O₄-based electrochemical sensors. It is understood that synthesis methods, surface morphology, crystallinity, defects, and interfacial composition influence sensing performance. Various preparation methods such as hydrothermal, sol-gel, co-precipitation, microwave-assisted, sonochemical, electrodeposition, and thermal decomposition have been briefly discussed. The analytical sensing performance of MnFe₂O₄ incorporated with carbon materials, polymers, metal-organic framework-derived materials, chitosan, and noble-metal nanoparticles (NPs) has been discussed for the detection of heavy metals, hydrogen peroxide, pharmaceuticals, pesticides, endocrine disruptors, and biomolecules. It is believed that MnFe₂O₄-based hybrid materials may exhibit improved conductivity, active surface area, analyte adsorption, and selectivity. Therefore, MnFe₂O₄-based hybrid materials demonstrate enhanced sensing performance. Subsequently, challenges and future perspectives have been discussed.