Huang Tingting, He Sheng, Ni Anji, Lian Tianquan, Lee Tang Ming
Department of Chemistry, University of Utah Salt Lake City UT 84112 USA
Department of Chemistry, Emory University 1515 Dickey Drive Northeast Atlanta Georgia 30322 USA
Chem Sci. 2024 Feb 27;15(12):4556-4563. doi: 10.1039/d3sc05408j. eCollection 2024 Mar 20.
Europium(iii) complexes are promising for bioimaging because of their long-lived, narrow emission. The photoluminescence (PL) from europium(iii) complexes is usually low. Thus, the effective utilization of low-energy light >400 nm and enhancement of PL are long-standing goals. Here, we show for the first time that 1-naphthoic acid triplet transmitter ligands bound to CdS quantum dots (QDs) and europium(iii) complexes create an energy transfer cascade that takes advantage of the strong QD absorption. This is confirmed by transient absorption spectroscopy, which shows hole mediated triplet energy transfer from QDs to 1-NCA, followed by triplet transfer from 1-NCA to europium(iii) complexes with an efficiency of 65.9 ± 7.7%. Smaller CdS QDs with a larger driving force lead to higher triplet transfer efficiency, with Eu(iii) PL intensity enhanced up to 21.4 times, the highest value ever reported. This hybrid QD system introduces an innovative approach to enhance the brightness of europium complexes.
铕（III）配合物因其长寿命、窄发射而有望用于生物成像。铕（III）配合物的光致发光（PL）通常较低。因此，有效利用大于400 nm的低能光并增强PL是长期目标。在此，我们首次表明，与硫化镉量子点（QDs）和铕（III）配合物结合的1-萘甲酸三重态传输配体形成了一个能量转移级联，利用了量子点的强吸收。瞬态吸收光谱证实了这一点，该光谱显示空穴介导的三重态能量从量子点转移到1-NCA，随后三重态从1-NCA转移到铕（III）配合物，效率为65.9±7.7%。具有更大驱动力的较小硫化镉量子点导致更高的三重态转移效率，铕（III）的PL强度增强高达21.4倍，这是有史以来报道的最高值。这种混合量子点系统引入了一种创新方法来提高铕配合物的亮度。
