Origin of Size-Dependent Energy Transfer from Photoexcited CdSe Quantum Dots to Gold Nanoparticles

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• 作者：Mariana Kondon ; Junhyung Kim ; Nayane Udawatte ; Dongil Lee
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：May 1, 2008
• 年：2008
• 卷：112
• 期：17
• 页码：6695 - 6699
• 全文大小：114K
• 年卷期：v.112,no.17(May 1, 2008)
• ISSN：1932-7455

文摘

The photoluminescence quenching of a CdSe quantum dot by hexanethiolate-monolayer-protected gold clusters(MPCs) with core diameters of 1.1-4.9 nm is described. Experimental evidence suggests that the quenchingoccurs via an energy transfer mechanism. The energy transfer quenching efficiencies of MPCs were comparedusing Stern-Volmer plots. The quenching constant (K_Q) obtained from the slope of the plot shows an enormousincrease from 2.5 × 10⁵ to 2.3 × 10⁸ M^-1 by nearly 1000-fold as the core size increases from 1.1 to 4.9 nm.The origin of the size dependence is considered. There is a remarkable linear correlation found between thequenching constant and the MPC core volume. This correlation suggests that the energy transfer quenchingefficiency is governed by the absorption cross-section of the MPC quencher that scales as its core volume.