Kuo Jason S, Kuyper Christopher L, Allen Peter B, Fiorini Gina S, Chiu Daniel T
Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
Electrophoresis. 2004 Nov;25(21-22):3796-804. doi: 10.1002/elps.200406118.
With advances in III-V nitride manufacturing processes, high-power light-emitting diode (LED) chips in the blue and UV wavelengths are now commercially available at reasonable cost and can be used as excitation sources in optical sensing. We describe the use of these high-power blue and UV LEDs for sensitive fluorescence detection, including chip-based flow cytometry, capillary electrophoresis (CE), and single-molecule imaging. By using a blue LED with a focusable power of approximately 40 mW as the excitation source for fluorescent beads, we demonstrate a simple chip-based bead sorter capable of enriching the concentration of green fluorescent beads from 63% to 95%. In CE experiments, we show that a mixture of analyte solution containing 30 nM 6-carboxyrhodamine 6G and 10 nM fluorescein can be separated and detected with excellent signal-to-noise ratio (approximately 17 for 10 nM fluorescein) using the collimated emission from a blue LED; the estimated mass detection limit was approximately 200 zmol for fluorescein. We also demonstrated ultrasensitive fluorescence imaging of single rhodamine 123 molecules and individual lambda-DNA molecules. At a small fraction of the cost of an Ar+ laser, high-power blue and UV LEDs are effective alternatives for lasers and arc lamps in fluorescence applications that demand portability, low cost, and convenience.
随着Ⅲ-Ⅴ族氮化物制造工艺的进步,蓝色和紫外波长的高功率发光二极管(LED)芯片现在已能以合理成本实现商业化,可作为光学传感中的激发源。我们描述了这些高功率蓝色和紫外LED在灵敏荧光检测中的应用,包括基于芯片的流式细胞术、毛细管电泳(CE)和单分子成像。通过使用聚焦功率约为40 mW的蓝色LED作为荧光微球的激发源,我们展示了一种简单的基于芯片的微球分选仪,它能够将绿色荧光微球的浓度从63%富集到95%。在CE实验中,我们表明,使用蓝色LED的准直发射光,可以分离并检测含有30 nM 6-羧基罗丹明6G和10 nM荧光素的分析物溶液混合物,其信噪比极佳(对于10 nM荧光素约为17);荧光素的估计质量检测限约为200 zmol。我们还展示了单个罗丹明123分子和单个λ-DNA分子的超灵敏荧光成像。高功率蓝色和紫外LED的成本仅为氩离子激光器的一小部分,对于要求便携性、低成本和便利性的荧光应用来说,它们是激光器和弧光灯的有效替代品。