Aggregation-Induced Emission Luminogen with Near-Infrared-II Excitation and Near-Infrared-I Emission for Ultradeep Intravital Two-Photon Microscopy
Aggregation-Induced Emission Luminogen with Near-Infrared-II Excitation and Near-Infrared-I Emission for Ultradeep Intravital Two-Photon Microscopy
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DOI：
10.1021/acsnano.8b02452
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发表时间：
2018-08-01
期刊：
影响因子：
17.1
通讯作者：
Tang, Ben Zhong
中科院分区：
文献类型：
--
作者：
Qi, Ji;Sun, Chaowei;Tang, Ben Zhong
目前，阻碍荧光技术大规模临床应用的一个严重问题是穿透深度浅。在较长波长近红外（NIR）区域（>1100 nm）激发和在 NIR-I 区域（650-950 nm）发射的双光子荧光显微成像是实现深层组织高分辨率成像的良好选择。在这里，我们报告了基于近红外聚集诱导发射发光体（AIEgen）的超深双光子荧光生物成像，具有 1300 nm NIR-II 激发和 NIR-I 发射（峰值类似于 810 nm）。蟹形AIEgen具有平面核心结构和多个扭曲的苯基/萘基旋转体，可提供高荧光量子产率和高效的双光子活性。有机AIE点表现出高稳定性、良好的生物相容性和1.22 x 10(3) GM的大双光子吸收截面。在1300 nm NIR-II激发下，体内双光子荧光显微成像有助于以亚3.5 μm的高空间分辨率重建白质（>840 μm）甚至海马（>960 μm）的3D脉管系统，并可视化小鼠大脑中约5 μm深至1065 μm的小血管，这是体内最大穿透深度和最佳空间分辨率之一双光子成像。与 AIE 点的合理比较表明，对于高分辨率深度成像，双光子成像优于单光子模式。这项工作将激发人们对开发用于深部组织生物医学成像的高效近红外荧光团的更多视野和见解。
Currently, a serious problem obstructing the large-scale clinical applications of fluorescence technique is the shallow penetration depth. Two-photon fluorescence microscopic imaging with excitation in the longer-wavelength near-infrared (NIR) region (>1100 nm) and emission in the NIR-I region (650-950 nm) is a good choice to realize deep-tissue and high-resolution imaging. Here, we report ultradeep two-photon fluorescence bioimaging with 1300 nm NIR-II excitation and NIR-I emission (peak similar to 810 nm) based on a NIR aggregation-induced emission luminogen (AIEgen). The crab-shaped AIEgen possesses a planar core structure and several twisting phenyl/naphthyl rotators, affording both high fluorescence quantum yield and efficient two-photon activity. The organic AIE dots show high stability, good biocompatibility, and a large two-photon absorption cross section of 1.22 x 10(3) GM. Under 1300 nm NIR-II excitation, in vivo two-photon fluorescence microscopic imaging helps to reconstruct the 3D vasculature with a high spatial resolution of sub-3.5 mu m beyond the white matter (>840 mu m) and even to the hippocampus (> 960 mu m) and visualize small vessels of similar to 5 mu m as deep as 1065 mu m in mouse brain, which is among the largest penetration depths and best spatial resolution of in vivo two-photon imaging. Rational comparison with the AIE dots manifests that two-photon imaging outperforms the one-photon mode for high-resolution deep imaging. This work will inspire more sight and insight into the development of efficient NIR fluorophores for deep-tissue biomedical imaging.