NIR-II fluorescence in vivo confocal microscopy with aggregation-induced emission dots

Wenbin Yu; Bing Guo; Hequn Zhang; Jing Zhou; Xiaoming Yu; Liang Zhu; Dingwei Xue; Wen Liu; Xianhe Sun; Jun Qian

doi:10.1016/j.scib.2019.02.019

NIR-II fluorescence in vivo confocal microscopy with aggregation-induced emission dots

Sci Bull (Beijing). 2019 Mar 30;64(6):410-416. doi: 10.1016/j.scib.2019.02.019. Epub 2019 Feb 23.

Authors

Wenbin Yu¹, Bing Guo², Hequn Zhang¹, Jing Zhou¹, Xiaoming Yu³, Liang Zhu⁴, Dingwei Xue³, Wen Liu¹, Xianhe Sun¹, Jun Qian⁵

Affiliations

¹ State Key Laboratory of Modern Optical Instrumentations, Centre for Optical and Electromagnetic Research, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310058, China.
² Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore.
³ Department of Urology, Sir Run-Run Shaw Hospital College of Medicine, Innovation Center for Minimally Invasive Technique and Device, Zhejiang University, Hangzhou 310016, China.
⁴ Interdisciplinary Institute of Neuroscience and Technology (ZIINT), Zhejiang University, Hangzhou 310058, China.
⁵ State Key Laboratory of Modern Optical Instrumentations, Centre for Optical and Electromagnetic Research, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310058, China; Joint Research Laboratory of Optics of Zhejiang, Normal University and Zhejiang University, Zhejiang Normal University, Jinhua 321000, China. Electronic address: qianjun@zju.edu.cn.

PMID: 36659732
DOI: 10.1016/j.scib.2019.02.019

Abstract

Significantly reduced tissue scattering of fluorescence signals in the second near-infrared (NIR-II, 1,000-1,700 nm) spectral region offers opportunities for large-depth in vivo bioimaging. Nowadays, most reported works concerning NIR-II fluorescence in vivo bioimaging are realized by wide-field illumination and 2D-arrayed detection (e.g., via InGaAs camera), which has high temporal resolution but limited spatial resolution due to out-of-focus signals. Combining NIR-II fluorescence imaging with confocal microscopy is a good approach to achieve high-spatial resolution visualization of biosamples even at deep tissues. In this presented work, a NIR-II fluorescence confocal microscopic system was setup. By using a kind of aggregation-induced emission (AIE) dots as NIR-II fluorescent probes, 800 μm-deep 3D in vivo cerebrovascular imaging of a mouse was obtained, and the spatial resolution at 700 μm depth could reach 8.78 μm. Moreover, the time-correlated single photon counting (TCSPC) technique and femtosecond laser excitation were introduced into NIR-II fluorescence confocal microscopy, and in vivo confocal NIR-II fluorescence lifetime microscopic imaging (FLIM) of mouse cerebral vasculature was successfully realized.

Keywords: AIE dots; Confocal microscopy; FLIM imaging; In vivo cerebrovascular imaging; NIR-II fluorescence; TCSPC.