Cerium Valence-Gated Interfacial Exciton Reconstruction for Fluorescence Modulation

Interfacial electronic coupling plays a decisive role in governing excited-state evolution and signal transduction in optoelectronic systems, yet dynamically adaptive interfaces driven by valence-state evolution remain largely unexplored in fluorescent sensing platforms. Herein, an Eu-functionalized Ce-MOF/CTF heterointerface is constructed to establish a valence-responsive optoelectronic system for dual-mode H₂O₂ sensing. Upon oxidative stimulation, the Ce-MOF/CTF heterointerface dynamically reconstructs the interfacial charge-transfer network through Ce³⁺/Ce⁴⁺ valence-state evolution, enabling modulation of electron migration across the interface and synchronously regulating Eu-centered luminescence, CTF-derived fluorescence, and nanozyme-mediated catalytic outputs. The results reveal that oxidative valence evolution induces adaptive interfacial electronic redistribution and excited-state pathway reconstruction, thereby amplifying microscopic electronic perturbations into programmable fluorescence-catalytic responses. Beyond conventional sensing systems dominated by static emissive centers, this work demonstrates that adaptive interface states can function as dynamic optoelectronic units for intelligent signal transduction. Furthermore, the interfacial optical response can be integrated into flexible electrospun membranes and machine-learning-assisted visual recognition systems, enabling portable dual-mode visual sensing. This work provides a new perspective for constructing adaptive optoelectronic interfaces through valence-state engineering and establishes a general framework for next-generation intelligent sensing platforms.