Self-Calibrated Identification of Metastatic Lymph Nodes Using Full-NIR-II Tunable Ag₂Se Quantum Dots Engineered by...

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Materials Science

Background:

• Ratiometric fluorescence imaging in the second near-infrared (NIR-II) region offers potential for identifying metastatic lymph nodes (MLNs).
• Current challenges include designing biocompatible probes with simple composition and broad spectral tunability.

Purpose of the Study:

• To develop a minimalist, self-calibrating ratiometric probe for enhanced MLN detection.
• To achieve broad spectral tunability and ensure biocompatibility for advanced diagnostics.

Main Methods:

• Synthesized homologous silver selenide (Ag₂Se) quantum dots (QDs) with controlled size-dependent emission.
• Utilized tributylphosphine-mediated coordination kinetics for emission tuning across 935-1710 nm.
• Coated Ag₂Se QDs with poly(amino acid) for improved biosafety, validated by in vitro and in vivo assays.

Main Results:

• Achieved continuous, size-dependent emission tuning of Ag₂Se QDs across the NIR-II region (935-1710 nm).
• Developed two spectrally distinct QDs (1040 nm and 1305 nm) for multiplexed imaging.
• Demonstrated real-time intraoperative and postoperative MLN detection with a diagnostic threshold ratio of ≈0.9.

Conclusions:

• Presented a scalable strategy for synthesizing full-NIR-II monochromatic QDs.
• Established a minimal-component, biocompatible platform for precision ratiometric diagnostics.
• The developed probe enables accurate identification of MLNs with high biosafety.