Photoenhancement of lifetimes in CdSe/ZnS and CdTe quantum dot-dopamine conjugates.
The response of water-soluble, mercaptocarboxylic acid-capped fluorescent semiconductor nanoparticles, or quantum dots (QDs), to extended visible-light irradiation is variable and poorly described. Here we use time-resolved spectroscopy to investigate the photoluminescence intensities and lifetimes of CdSe/ZnS and CdTe QDs as a function of blue light illumination. Conjugates of the particles to the electron donor dopamine were also investigated, and the effect of the antioxidant beta-mercaptoethanol was explored. Both types of QD showed signs of direct electron transfer to the conjugate, but enhancement was much more pronounced in CdSe/ZnS. A model of the two different types of enhancement is proposed.
Cooper
Daniel R
DR
Department of Biomedical Engineering, McGill University, 3775 Rue University, Montreal, QC H3A 2B4, Canada. daniel.cooper@mail.mcgill.ca
Suffern
Diana
D
Carlini
Lina
L
Clarke
Samuel J
SJ
Parbhoo
Rupesh
R
Bradforth
Stephen E
SE
Nadeau
Jay L
JL
D019187:Cadmium Compounds / Q000737:chemistry*; D004298:Dopamine / Q000737:chemistry*; D049449:Luminescence; D010100:Oxygen / Q000737:chemistry; D017785:Photons; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*; D013997:Time Factors; D017967:Zinc Compounds / Q000737:chemistry*
D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide; D013691:Tellurium; D010100:Oxygen; C028337:cadmium telluride; D004298:Dopamine