Encapsulated Energy-Transfer Cassettes with Extremely Well Resolved Fluorescent Outputs

详细信息    查看全文

• 作者：Yuichiro Ueno ; Jiney Jose ; Aurore Loudet ; C茅sar P茅rez-Bol铆var ; Pavel Anzenbacher ; Jr. ; Kevin Burgess
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：January 12, 2011
• 年：2011
• 卷：133
• 期：1
• 页码：51-55
• 全文大小：305K
• 年卷期：v.133,no.1(January 12, 2011)
• ISSN：1520-5126

文摘

This paper concerns the development of water-compatible fluorescent imaging probes with tunable photonic properties that can be excited at a single wavelength. Bichromophoric cassettes 1a鈭?b>1c consisting of a BODIPY donor and a cyanine acceptor were prepared using a simple synthetic route, and their photophysical properties were investigated. Upon excitation of the BODIPY moiety at 488 nm the excitation energy is transferred through an acetylene bridge to the cyanine dye acceptor, which emits light at approximately 600, 700, and 800 nm, i.e., with remarkable dispersions. This effect is facilitated by efficient energy transfer that gives a 鈥渜uasi-Stokes鈥?shift between 86 and 290 nm, opening a huge spectral window for imaging. The emissive properties of the cassettes depend on the energy-transfer (ET) mechanism: the faster the transfer, the more efficient it is. Measurements of rates of ET indicate that a through-bond ET takes place in the cassettes 1a and 1b that is 2 orders of magnitude faster than the classical through-space, F枚rster ET. In the case of cassette 1c, however, both mechanisms are possible, and the rate measurements do not allow us to discern between them. Thus, the cassettes 1a鈭?b>1c are well suited for multiplexing experiments in biotechnological methods that involve a single laser excitation source. However, for widespread application of these probes, their solubility in aqueous media must be improved. Consequently, the probes were encapsulated in calcium phosphate/silicate nanoparticles (diameter ca. 22 nm) that are freely dispersible in water. This encapsulation process resulted in only minor changes in the photophysical properties of the cassettes. The system based on cassette 1a was chosen to probe how effectively these nanoparticles could be used to deliver the dyes into cells. Encapsulated cassette 1a permeated Clone 9 rat liver cells, where it localized in the mitochondria and fluoresced through the acceptor part, i.e., red. Overall, this paper reports readily accessible, cyanine-based through-bond ET cassettes that are lypophilic but can be encapsulated to form nanoparticles that disperse freely in water. These particles can be used to enter cells and to label organelles.