Radiation-Luminescence-Excited Quantum Dots for in vivo Multiplexed Optical Imaging
Radiation-Luminescence-Excited Quantum Dots for in vivo Multiplexed Optical Imaging
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DOI：
10.1002/smll.200902408
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发表时间：
2010-05-21
期刊：
影响因子：
13.3
通讯作者：
Cheng, Zhen
中科院分区：
文献类型：
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作者：
Liu, Hongguang;Zhang, Xiaofen;Cheng, Zhen
半导体纳米晶体、量子点 (QD) 表现出许多有利的特性，包括尺寸依赖性可调谐发射带、宽激发光谱、大摩尔消光系数、高荧光量子产率、大有效斯托克斯位移和高光稳定性。 [1]最近，量子点因其潜在的生物医学应用而备受关注，并作为有效的荧光传感器被广泛探索，用于实时检测生物分子、生物组织染色以及体外和体内生物途径或疾病进展的分子成像。 [2]然而，与许多其他荧光探针一样，需要外部光来照射量子点以产生荧光信号。由于强背景自荧光、激发光子的组织穿透性差以及这些光子在组织中的显着吸收和散射，这限制了量子点的体内使用。为了解决这些问题，无需外部激发即可发射红光至近红外（NIR）光的自发光量子点共轭物将是理想的选择。通过模仿自然生物发光共振能量转移 (BRET) 过程，已经描述了几种具有此类新颖特性的有前途的量子点缀合物。在该过程中，化学能转化为光子以激发量子点。 [3]这项有趣的工作启发我们进一步开发其他具有宽激发光谱的直接、特异性自发光量子点系统。许多放射性核素（18F、131/123I、99mTc、90Y等）已广泛应用于核医学中用于诊断或治疗目的。除了发射高能粒子或灰色粒子（keV 至 MeV）外，β 发射体（b+ 和 b+）等放射性核素被发现能够产生源自轫致辐射或切伦科夫辐射的连续波长的低能光。 [4]在这里，我们假设可见光和近红外窗口（1.2-3.1 eV，400-1000nm）中的放射性发光可以作为许多不同荧光团（例如量子点）照明的内部光源，并且产生的荧光发射可以用于光学成像（图1）。为了证明这一概念，选择了三种 CdSe/ZnS 核/壳 QD（QD655、QD705 和 QD800），并通过 ab 发射器 131I 进行辐照，用于体外和体内光学成像。
Semiconductor nanocrystals, quantum dots (QDs), exhibit many favorable characteristics including size-dependent tunable emission bands, broad excitation spectra, large molarextinction coefficient, high ffuorescence quantum yields, large effective Stokes shifts, and high photostability.[1] Recently, QDs have drawn much attention for their potential biomedical applications and have been widely explored as effective ffuorescent sensors for real-time detection of biomolecules, for the staining of biological tissues and for molecular imaging of biological pathways or disease progression in vitro and in vivo.[2] However, as with many other ffuorescence probes, external light is required to illuminate the QDs to produce a ffuorescent signal. This limits the in vivo use of QDs due to strong background autoffuorescence, poor tissue penetration of the excitation photons, as well as significant absorption and scattering of these photons in tissues. To circumvent these problems, self-illuminating QD conjugates that can emit red to near-infrared (NIR) light without external excitation would be ideal. Several promising QD conjugates with such novel characteristics have been described by mimicking a natural bioluminescence resonance energy transfer (BRET) process, in which chemical energy is converted into photons to excite the QDs.[3] This interesting work has inspired us to further develop other direct and specific self-illuminating QD systems with a broad excitation spectrum.Many radionuclides (18F, 131/123I, 99mTc, 90Y, etc.) have been widely used in nuclear medicine for diagnostic or therapeutic purposes. Besides emitting high-energy particles or grays (keV to MeV), radionuclides such as beta emitters (bþ and bÀ) have been found to be able to generate low-energy lights with continuous wavelengths that originate from Bremsstrahlung or Cerenkov radiation.[4] Here we hypothesize that the radioactive luminescent light in the visible and NIR window (1.2–3.1 eV, 400–1000nm) could serve as an internal source for illumination of many different ffuorophores such as QDs, and the resulting ffuorescent emissions can then be used for optical imaging (Figure 1). To prove this concept, three CdSe/ZnS core/shell QDs (QD655, QD705, and QD800) were selected and irradiated by ab À emitter, 131I, for in vitro and in vivo optical imaging.