Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.
Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California, USA.
J Biophotonics. 2022 Jan;15(1):e202100158. doi: 10.1002/jbio.202100158. Epub 2021 Oct 14.
Multiphoton microscopy using short-wave infrared (SWIR) radiation offers nondestructive and high-resolution imaging through tissue. Two-photon fluorescence (TPF), for example, is commonly employed to increase the penetration depth and spatial resolution of SWIR imaging, but the broad spectral peaks limit its multiplexing capabilities. Hyper-Raman scattering, the vibrational analog of TPF, yields spectral features on the order of 20 cm and reporter-functionalized noble metal nanoparticles (NPs) provide a platform for both hyper-Raman signal enhancement and selective targeting in biological media. Herein we report the first tissue imaging study employing surface-enhanced resonance hyper-Raman scattering (SERHRS), the two-photon analog of surface-enhanced resonance Raman scattering. Specifically, we employ multicore gold-silica NPs (Au@SiO NPs) functionalized with a near infrared-resonant cyanine dye, 3,3'-diethylthiatricarbocyanine iodide as a SERHRS reporter. SWIR SERHRS spectra are efficiently acquired from mouse spleen tissue. SWIR SERHRS combines two-photon imaging advantages with narrow vibrational peak widths, presenting future applications of multitargeted bioimaging.
利用短波长红外（SWIR）辐射的多光子显微镜技术可对组织进行非破坏性的高分辨率成像。例如，双光子荧光（TPF）常用于提高 SWIR 成像的穿透深度和空间分辨率，但宽的光谱峰限制了其复用能力。超拉曼散射是 TPF 的振动类似物，其光谱特征在 20cm 左右，而功能化的贵金属纳米颗粒（NPs）为超拉曼信号增强和生物介质中的选择性靶向提供了平台。本文报道了首例采用表面增强共振超拉曼散射（SERHRS）的组织成像研究，SERHRS 是表面增强共振拉曼散射的双光子类似物。具体来说，我们使用近红外共振菁染料 3,3'-二乙基噻二碳菁碘化物功能化的多核金-硅纳米颗粒（Au@SiO NPs）作为 SERHRS 报告分子。从小鼠脾脏组织中高效地获取了 SWIR SERHRS 光谱。SWIR SERHRS 结合了双光子成像的优势和窄的振动峰宽，为多靶向生物成像的未来应用提供了可能。
