Selection of quantum dot wavelengths for biomedical assays and imaging.
Selection of quantum dot wavelengths for biomedical assays and imaging.
复制标题
DOI：
10.1162/153535003765276282
复制
发表时间：
2003-01-01
影响因子：
2.8
通讯作者：
Frangioni, John V
中科院分区：
文献类型：
--
作者：
Lim, Yong Taik;Kim, Sungjee;Frangioni, John V
荧光半导体纳米晶体（量子点）被认为是生物医学检测和成像的优秀造影剂。量子点的一个独特性质是它们的吸光度随激发和发射波长之间的距离增加而增加。在体内使用量子点的热情源于这一特性，因为光子产率应该与宽带吸收的积分成正比。在这项研究中，我们证明了组织散射和吸光度有时可以抵消在较蓝波长处增加的量子点吸收，并抵消这种潜在的优势。通过使用先前验证的数学模型，我们探索了组织吸光度、组织散射、散射的波长依赖性、水-血红蛋白比和组织厚度对QD性能的影响。我们得出结论，当嵌入到生物流体和组织中时，量子点激发波长通常会受到很大的限制，并且应该根据特定的应用仔细选择激发和发射波长。在此基础上，我们制作了优化的近红外量子点，用于白光激发和硅CCD相机的表面血管成像，并将其用于活体冠状动脉血管成像。综上所述，我们的数据应该证明对设计针对特定生物医学应用优化的荧光QD造影剂是有用的。
Fluorescent semiconductor nanocrystals (quantum dots [QDs]) are hypothesized to be excellent contrast agents for biomedical assays and imaging. A unique property of QDs is that their absorbance increases with increasing separation between excitation and emission wavelengths. Much of the enthusiasm for using QDs in vivo stems from this property, since photon yield should be proportional to the integral of the broadband absorption. In this study, we demonstrate that tissue scatter and absorbance can sometimes offset increasing QD absorption at bluer wavelengths, and counteract this potential advantage. By using a previously validated mathematical model, we explored the effects of tissue absorbance, tissue scatter, wavelength dependence of the scatter, water-to-hemoglobin ratio, and tissue thickness on QD performance. We conclude that when embedded in biological fluids and tissues, QD excitation wavelengths will often be quite constrained, and that excitation and emission wavelengths should be selected carefully based on the particular application. Based on our results, we produced near-infrared QDs optimized for imaging surface vasculature with white light excitation and a silicon CCD camera, and used them to image the coronary vasculature in vivo. Taken together, our data should prove useful in designing fluorescent QD contrast agents optimized for specific biomedical applications.