Three-component Förster resonance energy transfer (FRET) has been used to obtain efficient FRET between the cationic conjugated polymer (CCP) as donor and 5-carboxy tetramethylrhodamine (TAMRA) dye as acceptor, by using an intermediate donor, fluorescein. In spite of the fact that there is enough overlap between the emission spectra of CCP and absorption spectra of TAMRA, the efficiency of FRET between CCP and TAMRA is poor. The reason for this is that while the Förster critical distance is not very sensitive to the overlap, the FRET efficiency is extremely sensitive to it. However, it is observed that the FRET efficiency between CCP and TAMRA improves considerably when fluorescein is introduced in the solution. The triple FRET so obtained can be used for deoxyribonucleic acid sequence detection in medical diagnostics because the fluorescence emission from TAMRA is pH-insensitive.

中文翻译：

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共轭聚合物和 TAMRA 染料之间能量转移的三重 FRET 技术在医学诊断中的可能应用

三组分福斯特共振能量转移 (FRET) 已被用于通过使用中间体供体荧光素在作为供体的阳离子共轭聚合物 (CCP) 和作为受体的 5-羧基四甲基罗丹明 (TAMRA) 染料之间获得有效的 FRET。尽管 CCP 的发射光谱和 TAMRA 的吸收光谱之间有足够的重叠，但 CCP 和 TAMRA 之间的 FRET 效率很差。这样做的原因是，虽然 Förster 临界距离对重叠不是很敏感，但 FRET 效率对其非常敏感。然而，据观察，当溶液中引入荧光素时，CCP 和 TAMRA 之间的 FRET 效率显着提高。