Photoinduced energy transfer between water-soluble CdTe quantum dots and aluminium tetrasulfonated phthalocyanine
作者:Mopelola Idowu、Ji -Yao Chen、Tebello Nyokong
DOI:10.1039/b707808k
日期:——
Thiol stabilized CdTe quantum dots (QDs) synthesized in aqueous phase were used as energy donors to aluminium tetrasulfonated phthalocyanine (AlTSPc) through fluorescence resonance energy transfer (FRET). Energy transfer occurred from the QDs to AlTSPc upon photoexcitation of the QDs. An enhancement in efficiency of energy transfer with the nature of the carboxylic thiol stabilizers on the QDs was observed. The results showed that for enhanced FRET to occur, the donor–acceptor distance has to be lower than the critical distance. The quenching constant K as well as the binding constant kb values were calculated suggesting strong interaction of the QDs with the AlTSPc. Study of the photophysics of AlTSPc in the presence of the QDs revealed a high triplet state yield, hence the possibility of using QDs in combination with phthalocyanines as photosensitizers in photodynamic therapy. The triplet state lifetimes of AlTSPc in the presence of the QDs were calculated and the lifetime in the presence of CdTe capped with 3-mercaptopropionic acid (MPA) was found to be the longest. MPA capped QD in a mixture with AlTSPc resulted in long triplet lifetime and high triplet yield of the latter, and high energy transfer efficiency, hence was found to be most suitable as a potential candidate for photodynamic therapy of cancer studies.
在水相中合成的硫醇稳定碲化镉量子点(QDs)被用作能量供体,通过荧光共振能量转移(FRET)作用于四磺化铝酞菁(AlTSPc)。当 QDs 受到光激发时,能量从 QDs 转移到 AlTSPc。根据 QDs 上羧基硫醇稳定剂的性质,观察到能量转移的效率有所提高。结果表明,要增强 FRET,供体-受体距离必须低于临界距离。计算得出的淬灭常数 K 和结合常数 kb 值表明,QDs 与 AlTSPc 之间存在很强的相互作用。对 AlTSPc 在 QDs 存在下的光物理研究表明,AlTSPc 具有很高的三重态产率,因此有可能将 QDs 与酞菁结合用作光动力疗法中的光敏剂。计算了存在 QDs 时 AlTSPc 的三重态寿命,发现存在用 3-巯基丙酸(MPA)封端的 CdTe 时的寿命最长。MPA 封顶的 QD 与 AlTSPc 混合后,后者的三重态寿命长、三重态产量高、能量传递效率高,因此最适合作为癌症光动力疗法研究的潜在候选物质。