Hierarchical MnS@MoS₂ architectures on tea bag filter paper for flexible, sensitive, and selective non-enzymatic hydrogen peroxide sensors

We report here the rational development of MnO₂ nanorods coated tea bag filter paper (TBFP) as a self-standing, bendable, and disposable electrochemical probe for the sensitive and selective H₂O₂ detection and addresses their challenges in H₂O₂ sensing via the replacement of ‘O’ with ‘S’ in the form of MnS microcubes and its core@shell architecture with MoS₂. The as-configured MnS@MoS₂/TBFP overwhelms the constrains of conventional electrochemical probes including time and cost consumed electrode surface renewability and catalyst loading progression, and the practice of an insulating binder. The hierarchical open porous architectures of MoS₂-shell favour the diffusion of H₂O₂ into the core-MnS microcubes, facilitating an analyte utilization efficacy at both the core and shell architectures. The impacts of core@shell morphological features, replacement of ‘O’ with ‘S’, surface defects, and lattice distribution of MnS@MoS₂ toward non-enzymatic H₂O₂ sensing performances are elucidated using variant electrochemical techniques. With the synergism of uniformly implanted and exposed metallic active sites, efficient electron transfer rate, and high analyte utilization efficiency, MnS@MoS₂/TBFP exposes the low detection limit (120 nM), excellent sensitivity (650 μA mM⁻¹ cm⁻²), and wide linear range (500 nM-5 mM) on H₂O₂ detection. Furthermore, the scrutinized non-enzymatic H₂O₂ detection concerts of MnS/MoS₂/TBFP are selective, decisive, repeatable, and stable, constructing the excellent recovery rates in human urine sample analyses. Thus, the collective benefits of free-standing, flexible, binder-less, re-functional, and cost-efficient MnS@MoS₂/TBFP probe actualize the evolution of affordable and high performance H₂O₂ sensors.