Unlocking Multimodal Nonlinear Microscopy for Deep‐Tissue Imaging under Continuous‐Wave Excitation with Tunable Upconverting Nanoparticles
Abstract
Abstract Nonlinear microscopy provides excellent depth penetration and axial sectioning for 3D imaging, yet widespread adoption is limited by reliance on expensive ultrafast pulsed lasers. This work circumvents such limitations by employing rare‐earth doped upconverting nanoparticles (UCNPs), specifically Yb 3+ /Tm 3+ co‐doped NaYF 4 nanocrystals, which exhibit strong multimodal nonlinear optical responses under continuous‐wave (CW) excitation. These UCNPs emit multiple wavelengths at UV (λ ≈ 450 nm), blue (λ ≈ 450 nm), and NIR (λ ≈ 800 nm), whose intensities are nonlinearly governed by excitation power. Exploiting these properties, multi‐colored nonlinear emissions enable functional imaging of cerebral blood vessels in deep brain. Using a simple optical setup, high resolution in vivo 3D imaging of mouse cerebrovascular networks at depths up to 800 µmm is achieved, surpassing performance of conventional imaging methods using CW lasers. In vivo cerebrovascular flow dynamics is also visualized with wide‐field video‐rate imaging under low‐powered CW excitation. Furthermore, UCNPs enable depth‐selective, 3D‐localized photo‐modulation through turbid media, presenting spatiotemporally targeted light beacons. This innovative approach, leveraging UCNPs' intrinsic nonlinear optical characteristics, significantly advances multimodal nonlinear microscopy with CW lasers, opening new opportunities in bio‐imaging, remote optogenetics, and photodynamic therapy.
Article Details
Authors (14)
Jeongmo Kim
Laboratoire de Physique de la Matière Condensée—CNRS, Ecole Polytechnique, Institut Polytechnique de Paris
Seunghun Lee
Yundon Jeong
Department of Biomedical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Kyunghwan Kim
Department of Chemistry Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Kibum Nam
Hyungwon Jin
Department of Biomedical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Yuha Choi
Department of Biomedical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Hyun‐Jin Kim
Department of Biological Sciences Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Heungjin Ryu
Department of Biomedical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Ki Hean Kim
Division of Integrative Biosciences and Biotechnology Pohang University of Science and Technology 77 Cheongam‐Ro, Nam‐gu Pohang Gyeongbuk 37673 Republic of Korea
Jae‐Ick Kim
Department of Biological Sciences Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Jongnam Park
School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Jinmyoung Joo
Department of Biomedical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 Republic of Korea
Jung‐Hoon Park
Department of Convergence Medicine, Asan Medical Center University of Ulsan College of Medicine Seoul Republic of Korea