Bumb Ambika, Sarkar Susanta K, Wu Xufeng S, Brechbiel Martin W, Neuman Keir C
Biomed Opt Express. 2011 Oct 1;2(10):2761-9. doi: 10.1364/BOE.2.002761. Epub 2011 Sep 12.
Multi-modal nanoparticles incorporating fluorophores are increasingly being used for medical applications. The number of fluorophores incorporated into the nanoparticles during synthesis is stochastic, leaving some nanoparticles devoid of fluorophores. Determining the number, the brightness and the photostability of the fluorophores incorporated, and the percentage of labeled nanoparticles (labeling efficiency) remains challenging. We have determined the aforementioned quantities for two synthesized multi-modal nanoparticles by exploiting the photobleaching of fluorophores at the single-molecule level using a total internal reflection fluorescence microscope. Labeling efficiency was determined by fitting the distribution of incorporated fluorophores with a statistical model and verified by independent experiments.
包含荧光团的多模态纳米颗粒越来越多地用于医学应用。在合成过程中纳入纳米颗粒的荧光团数量是随机的，导致一些纳米颗粒不含荧光团。确定纳入的荧光团数量、亮度和光稳定性，以及标记纳米颗粒的百分比（标记效率）仍然具有挑战性。我们通过使用全内反射荧光显微镜在单分子水平上利用荧光团的光漂白，确定了两种合成的多模态纳米颗粒的上述量。通过用统计模型拟合纳入荧光团的分布来确定标记效率，并通过独立实验进行验证。
