Lanthanide MOF‐Perovskite Quantum‐Cutting Circularly Polarized Emitters for Vital Sensing and AI‐Assisted Emotion Recognition

ABSTRACT Metal‐organic frameworks (MOFs) are widely deployed in catalysis, separation and chemical sensing, yet luminescent MOFs, especially those emitting near‐infrared (NIR) circularly polarized luminescence (CPL), remain largely underexplored. Here, we address this critical gap through a hierarchical dual‐sphere engineering strategy to fabricate luminescent Eu‐Yb‐BTC MOFs, wherein L‐phenylalanine serves as a second‐sphere modulator to construct low‐symmetry chiral microenvironments surrounding lanthanide centers. Subsequent hybridization with Yb‐doped perovskite quantum dots synergistically enhances both quantum‐cutting efficiency and CPL performance, yielding a 170% enhancement in the 980 nm Yb 3+ emission, an absolute photoluminescence quantum yield of 154%, and a luminescence dissymmetry factor of ‐1.58 × 10 −2 . Leveraging its single‐source RED‐NIR dual‐band CPL output, whose inherent polarization selectivity suppresses stray light and ambient background noise to enable more accurate blood oxygen monitoring, we demonstrate a portable blood oxygen sensor with 15 s response and <1.5% measurement error, and further develop an AI‐assisted emotion recognition framework based on dual‐channel photoplethysmography signals. This work establishes a versatile design paradigm for high‐performance chiral luminescent MOFs, opening new avenues for next‐generation wearable biomedical diagnostics and edge‐AI‐enabled healthcare.