2025-07-03 名古屋大学
図1 粒子組成の精密制御と表面被覆によって作製した近赤外発光Ag8GeS6量子ドットと生体深部イメージング(模式図)
<関連情報>
- https://www.nagoya-u.ac.jp/researchinfo/result/2025/07/-ag8ges6.html
- https://www.nagoya-u.ac.jp/researchinfo/result/upload_images/20250703_engg.pdf
- https://onlinelibrary.wiley.com/doi/10.1002/smll.202411142
Ag8GeS6量子ドットの近赤外フォトルミネッセンスの組成微調整とZnSコーティングによる生体内イメージングへの応用 Enhancing Near-Infrared Photoluminescence of Ag8GeS6 Quantum Dots Through Compositional Fine-Tuning and ZnS Coating for In Vivo Bioimaging
Nurmanita Rismaningsih, Junya Kubo, Masayuki Soto, Kazutaka Akiyoshi, Tatsuya Kameyama, Takahisa Yamamoto, Hiroshi Yukawa, Yoshinobu Baba, Tsukasa Torimoto
Small Published: 07 May 2025
DOI:https://doi.org/10.1002/smll.202411142
Abstract
Quantum dots (QDs) composed of a group I–IV–VI semiconductor, Ag8GeS6, have been intensively investigated for constructing efficient energy conversion systems. However, their potential for photoluminescence (PL)-based applications has remained unexplored. Herein, the first successful preparation of Ag8GeS6 QDs exhibiting near-infrared (NIR) PL is reported. These Ag8GeS6 QDs with an average diameter of 4.2–4.6 nm has an almost constant energy gap at 1.48–1.45 eV, even when the Ge/(Ag+Ge) precursor ratio is varied from 0.05 to 0.90. A significant PL peak is observed at 920 nm, the intensity being enlarged with an increase in the Ge/(Ag+Ge) ratio. The use of Ag8GeS6 QDs prepared with Ge/(Ag+Ge) = 0.82 in the precursors result in a PL quantum yield (QY) of 11%, which is further enhanced to 40% through surface coating with a ZnS shell of 1.0 nm in thickness, with the PL peak wavelength being slightly blue-shifted to 900 nm. Following surface modification with 3-mercaptopropionic acid for homogeneous dispersion in aqueous solutions, the Ag8GeS6@ZnS QDs are utilized as an NIR PL probe for in vivo bioimaging. PL signals are clearly detected from depths of at least 15 mm beneath the back skin of a mouse, demonstrating their deep-tissue imaging capability.
