On the Quenching of Semiconductor Quantum Dot Photoluminescence by Proximal Gold Nanoparticles

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• 作者：Thomas Pons ; Igor L. Medintz ; Kim E. Sapsford ; Seiichiro Higashiya ; Amy F. Grimes ; Doug S. English ; Hedi Mattoussi
• 刊名：Nano Letters
• 出版年：2007
• 出版时间：October 2007
• 年：2007
• 卷：7
• 期：10
• 页码：3157 - 3164
• 全文大小：255K
• 年卷期：v.7,no.10(October 2007)
• ISSN：1530-6992

文摘

Luminescent quantum dots (QDs) were proven to be very effective fluorescence resonance energy transfer donors with an array of organicdye acceptors, and several fluorescence resonance energy transfer based biosensing assemblies utilizing QDs have been demonstrated in thepast few years. Conversely, gold nanoparticles (Au-NPs) are known for their capacity to induce strong fluorescence quenching of conventionaldye donors. Using a rigid variable-length polypeptide as a bifunctional biological linker, we monitor the photoluminescence quenching ofCdSe-ZnS QDs by Au-NP acceptors arrayed around the QD surface, where the center-to-center separation distance was varied over a broadrange of values (~50-200 Å). We measure the Au-NP-induced quenching rates for such QD conjugates using steady-state and time-resolvedfluorescence measurements and examine the results within the context of theoretical treatments based on the Förster dipole-dipole resonanceenergy transfer, dipole-metal particle energy transfer, and nanosurface energy transfer. Our results indicate that nonradiative quenching ofthe QD emission by proximal Au-NPs is due to long-distance dipole-metal interactions that extend significantly beyond the classical Försterrange, in agreement with previous studies using organic dye-Au-NP donor-acceptor pairs.