Department of Chemical and Biological Engineering, 303 Furnas Hall, The University at Buffalo, The State University of New York, Buffalo, New York 14260-4200, USA.
Nanoscale. 2012 Aug 21;4(16):5163-8. doi: 10.1039/c2nr31003a. Epub 2012 Jul 16.
Quantum dots are known for their superior optical properties; however, when transferred into aqueous media, their luminescent properties are frequently compromised. When encapsulated in micelles for bioimaging applications, luminescent silicon quantum dots can lose as much as 50% of their luminescence depending on the formulation used. Here, we create an energy transfer micelle platform that combines silicon quantum dots with an anthracene-based dye in the hydrophobic core of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG) micelles. These phospholipid micelles are water dispersible, stable, and surrounded by a PEGylated layer with modifiable functional groups. The spectroscopic properties of energy transfer between the anthracene donors and silicon quantum dot acceptors were analyzed based on the observed dependence of the steady-state emission spectrum on concentration ratio, excitation wavelength, pH, and temperature. The luminescence of silicon quantum dots from the core of a 150 nm micelle is enhanced by more than 80% when the anthracene dye is added. This work provides a simple yet readily applicable solution to the long-standing problem of luminescence enhancement of silicon quantum dots and can serve as a template for improving the quantum dot emission yield for biological applications where luminescence signal enhancements are desirable and for solar applications where energy transfer plays a critical role in device performance.
量子点以其优异的光学性质而闻名；然而，当它们被转移到水介质中时，其发光性质经常会受到影响。当用于生物成像应用时，将发光硅量子点封装在胶束中，其发光强度可能会根据所用配方降低多达 50%。在这里，我们创建了一个能量转移胶束平台，将硅量子点与基于蒽的染料结合在 1,2-二硬脂酰-sn-甘油-3-磷酸乙醇胺-N-[甲氧基（聚乙二醇）-2000]（DSPE-PEG）胶束的疏水核中。这些磷脂胶束是水分散的、稳定的，并且被具有可修饰官能团的聚乙二醇化层包围。基于稳态发射光谱对浓度比、激发波长、pH 值和温度的依赖性，分析了蒽供体和硅量子点受体之间能量转移的光谱性质。当添加蒽染料时，来自 150nm 胶束核心的硅量子点的发光强度增强了 80%以上。这项工作为硅量子点发光增强的长期问题提供了一个简单但易于应用的解决方案，可作为提高生物应用中量子点发射产率的模板，在这些应用中，发光信号增强是理想的，并且在太阳能应用中，能量转移在器件性能中起着关键作用。
