Bright, Biocompatible NIR-II-Emitting I–VI Quantum Dots for Rapid Disease Diagnosis

ConspectusRapid diagnostic technology serves as a cornerstone of clinical medicine, playing an essential role in the early detection of major diseases and the development of personalized treatment strategies. The complexity and diversity of clinical diagnostic needs impose increasingly stringent demands on the timeliness, sensitivity, and specificity of detection techniques─requirements that current methods often fail to fully satisfy. Near-infrared II (NIR-II) fluorescence imaging has emerged as a highly promising visualization tool for rapid diagnosis, owing to its deep tissue penetration, high spatial resolution, excellent signal-to-background ratio, and real-time feedback capabilities. As advanced fluorescent nanomaterials, quantum dots (QDs) provide a powerful technological pathway to address the aforementioned clinical challenges. This Account systematically summarizes our recent research progress in this field from three key perspectives: First, we outline the design strategies, photophysical properties, and biosafety profiles of NIR-II-emitting I-VI QDs. Second, we comprehensively discuss strategies for achieving rapid and highly sensitive fluorescence detection, including self-assembly based multivalent anchoring, competitive absorption suppression, and mechanisms such as fluorescence resonance energy transfer (FRET) and chemiluminescence resonance energy transfer (CRET). Furthermore, representative applications of these technologies in in vivo visualization and clinical sample diagnostics are summarized, covering precise tumor margin delineation and micrometastasis detection, dynamic monitoring of vascular pathologies, and early assessment of inflammation and injury. Finally, we highlight the advantages of NIR-II fluorescent probes in diagnostic research, critically analyze existing challenges, and offer insights into future developmental directions.