Alkyl chain elongation engineering: Unlocking high‐brightness NIR‐II O‐xanthene dyes for in vivo bioimaging
- 1Key Laboratory of Green Chemistry and Technology Ministry of Education College of Chemistry Sichuan University Chengdu China
- 2Department of Chemistry Sichuan Engineering Research Center of Molecular Targeted Diagnostic & Therapeutic Drugs Xihua University Chengdu China
Abstract
NIR‐II fluorescent probes are powerful tools for advanced imaging, with performance governed by molar extinction coefficient (ε), quantum yield (Φ), and brightness (ε × Φ). However, achieving high brightness remains a major challenge. Here we report SCU‐OX‐Hex, a D–A–D probe with an O‐xanthene acceptor and an N‐alkylated aniline donor. Elongating the N‐alkyl chain enhances Φ and brightness while suppressing aggregation‐caused quenching. SCU‐OX‐Hex exhibits ε = 1.71 × 105 M−1 cm−1, Φ = 0.57%, and a brightness of 974.7 M−1 cm−1—among the highest reported for organic NIR‐II probes. In vivo, it enables high‐resolution imaging of the abdominal vasculature, the gastrointestinal tract, and tumor angiogenesis. In a lymph node metastasis model, it provides superior contrast and resolution compared with ICG, enabling precise intraoperative identification. This work establishes SCU‐OX‐Hex as a high‐performance NIR‐II agent and offers a broadly applicable design strategy for next‐generation probes.
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BibTeX
@article{zhao2026alkyl,
title = {{Alkyl chain elongation engineering: Unlocking high‐brightness NIR‐II O‐xanthene dyes for in vivo bioimaging}},
author = {Yu Zhao and Hong Zhang and Ruirui Zhang and Wenli Xia and Zhouyu Wang and Jie Chen and Xiaoqi Yu and Kun Li},
journal = {Smart molecules : open access},
year = {2026},
month = oct,
doi = {10.1002/smo2.70117},
url = {https://europepmc.org/article/PMC/PMC13719896},
note = {CC BY},
}
RIS
TY - JOUR
TI - Alkyl chain elongation engineering: Unlocking high‐brightness NIR‐II O‐xanthene dyes for in vivo bioimaging
AU - Yu Zhao
AU - Hong Zhang
AU - Ruirui Zhang
AU - Wenli Xia
AU - Zhouyu Wang
AU - Jie Chen
AU - Xiaoqi Yu
AU - Kun Li
PY - 2026
DA - 2026/10/29
JO - Smart molecules : open access
DO - 10.1002/smo2.70117
UR - https://europepmc.org/article/PMC/PMC13719896
AB - NIR‐II fluorescent probes are powerful tools for advanced imaging, with performance governed by molar extinction coefficient (ε), quantum yield (Φ), and brightness (ε × Φ). However, achieving high brightness remains a major challenge. Here we report SCU‐OX‐Hex, a D–A–D probe with an O‐xanthene acceptor and an N‐alkylated aniline donor. Elongating the N‐alkyl chain enhances Φ and brightness while suppressing aggregation‐caused quenching. SCU‐OX‐Hex exhibits ε = 1.71 × 105 M−1 cm−1, Φ = 0.57%, and a brightness of 974.7 M−1 cm−1—among the highest reported for organic NIR‐II probes. In vivo, it enables high‐resolution imaging of the abdominal vasculature, the gastrointestinal tract, and tumor angiogenesis. In a lymph node metastasis model, it provides superior contrast and resolution compared with ICG, enabling precise intraoperative identification. This work establishes SCU‐OX‐Hex as a high‐performance NIR‐II agent and offers a broadly applicable design strategy for next‐generation probes.
SN - 2751-4595
SN - 2751-4587
ER -