+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Synthesis, characterization, and self-organization of dendrimer-encapsulated HgTe quantum dots

, : Synthesis, characterization, and self-organization of dendrimer-encapsulated HgTe quantum dots. Langmuir 26(13): 10636-10644

Mercury telluride (HgTe) quantum dots (QDs) were synthesized in methanol at 5 degrees C using generation 5 (G5) and 7 (G7) polyamidoamine (PAMAM) dendrimers, which function both as nucleation sites and as nanoparticle stabilizers. Transmission electron microscopy (TEM) data indicate these particles were slightly oblate, with an average aspect ratio of 1.3 +/- 0.1 and a minor axis of 2.6 +/- 0.3 nm. The crystal phase was determined to be coloradoite (cubic system) by analysis of the electron diffraction pattern. Absorption maxima for HgTe QDs ranged from 950 to 970 nm, depending on the dendrimer generation and concentration. QD size distribution was optimized by careful variation of the Hg(2+):dendrimer surface group molar ratio for both G5 and G7 dendrimers. An increase in molar ratio from 1:0.5 to 1:4 resulted in a decrease in the half-width at half-maximum (HWHM) of the HgTe bandgap absorption from 68 +/- 3 to 52 +/- 2 nm, indicating a size distribution focusing of 23 +/- 4%. Second-derivative analysis of HgTe QD FTIR absorption spectra suggested that the quantum dots were fully encapsulated by a single G7 dendrimer, whereas multiple G5 dendrimers were necessary to stabilize a single nanoparticle. TEM and FTIR data revealed that the HgTe QDs form two-dimensional necklace-type arrays through a self-organization process, which proceeds through interpenetration of dendritic arms. TEM data further indicated that the average nanonecklace contained 10-15 QDs with an average inter-QD separation of 1.3 +/- 0.7 nm and a total chain length of 46 +/- 6 nm.


PMID: 20481491

DOI: 10.1021/la100866z

Other references

Berkovic, S.F.; Scheffer, I.E., 1998: Febrile seizures: genetics and relationship to other epilepsy syndromes. The relationship between febrile seizures and epilepsy has long been debated. We argue that there is some specificity to the types of epilepsy that follow febrile seizures, rather than febrile seizures being a nonspecific marker of a lowered seizu...

Henzell, R.; Lauren, D.; Hall, W., 1976: Laboratory tests with the insect growth regulator, diflubenzuron, against white fringed weevil adults and army caterpillar larvae. Proceedings 9th 143-147

Holik, K., 1951: Report from the Znojmo district. Zdravotnicka Revue; Vestnik Ministerstva Zdravotnictvi 26(11-12): 229-230

Mashkovskii, M.D.; Abramova, P.N., 1956: Pharmacological characteristics of isopromedol. Farmakologiia i Toksikologiia 19(3): 26-32

Rovira, A.R.; Fin, A.; Tor, Y., 2017: Expanding a fluorescent RNA alphabet: synthesis, photophysics and utility of isothiazole-derived purine nucleoside surrogates. A series of emissive ribonucleoside purine mimics, all comprised of an isothiazolo[4,3-<i>d</i>]pyrimidine core, was prepared using a divergent pathway involving a key Thorpe-Ziegler cyclization. In addition to an adenosine and a guano...

Abbey, A.; Buck, P.O.; Saenz, C., 2003: The role of alcohol in young adults judgments about unprotected sexual intercourse. Alcoholism Clinical & Experimental Research 27(5 Supplement): 172A, May

Richards, R.D., 1962: Lipids in diabetic retinopathy. Journal of the American Geriatrics Society 10: 831-842

Bhargava, K.S.; Joshi, R.D., 1962: Yellow mosaic, a virus disease of Rose in Gorakhpur. The 1st record of a rose virus disease in India, observed by staff of Gorakhpur Univ., Uttar Pradesh, in a local park in 1960, was followed by a survey which showed many local vars. to be infected. The disease, similar to rose yellow mosaic, was t...

Beggs, T.S.; Davis, P.J.; Verhoeyen, M.E., 1996: Delivery of therapeutic agents to a target site. Official Gazette of the United States Patent & Trademark Office Patents 1183(2): 812, Feb 13

Slack, C.; Lurix, K.; Lewis, S.; Lichten, L., 2006: Prenatal genetics: the evolution and future directions of screening and diagnosis. Journal of Perinatal & Neonatal Nursing 20(1): 93-97