Date of Award
Master of Science
Dr. Dongil Lee
Dr. Michael Barcelona
Dr. Steve Bertman
Masters Thesis-Open Access
The photoluminescence quenching of CdSe quantum dots (QD) and fluorescent dyes by hexanethiolate Mono layer Protected Clusters (MPCs) with core diameters of 1.1- 4 .9 nm is described.
The CdSe QD investigated had the following core diameters of 2.0, 2.6, 3.4 and 6.9 nm. The florescent dyes used were: Coumarin 440 (CM440), Fluorescein 548 (F548), Rhodamine 6G (R6G), Pyromethene 597 (PM597) and Lyssamine Dye (LD700). Experimental evidence suggests that the photoluminescence quenching of both CdSe QD and the fluorescent dyes occurs through energy transfer and that the AuMPCs are efficient quenchers in both cases. The larger MPCs are more efficient quenchers.
There is a remarkable linear correlation found between the quenching efficiency determined by Stem-Volmer plot and the MPC core volume which suggests that the quenching efficiency is governed by the MPC core-size dependent extinction cross-section that determines the spectral overlap between the emission of the donor (QD and fluorescent dyes) and the absorption of the MPC.
Kondon, "Origin of Size-Dependent Energy Transfer from Photoexcited CdSe Quantum Dots and Fluorescent Dyes to Gold Nanoparticles" (2008). Master's Theses. 5065.