Facile synthesis of water-soluble and size-homogeneous cadmium selenide nanoparticles and their application as a long-wavelength fluorescent probe for detection of Hg(II) in aqueous solution

Chen, Jinlong; Gao, Yingming; Guo, Chang; Wu, Guangxin; Chen, Youcun; Lin, Biwen

doi:10.1016/j.saa.2007.05.005

Cited by 21 publications

(8 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Table compares the PL intensity of dilute raw and purified suspensions after reaching stable values. The linear change in the PL from 1.7 × 10 6 to 2 × 10 4 when raw QDs were diluted by a factor of 100 with water was also observed for l -cysteine-capped CdSe QDs . The increase in the PL intensity of the raw QDs in order of increasing TGA solubilities from water to acetone shows that removing TGA from the surface in the presence of ions and ligand facilitates etching and passivation of individual dots.…”

Section: Results and Discussionsupporting

confidence: 58%

Solvent-Triggered Self-Assembly of CdTe Quantum Dots into Flat Ribbons

Jiang

Muscat

2013

J. Phys. Chem. C

View full text Add to dashboard Cite

Diluting an aqueous colloid containing purified CdTe quantum dots (QD) by injecting into common organic solvents triggered self-assembly into a variety of structures. Nanoribbons formed in methanol with aspect ratios near 1000 containing discrete dots lacking a packing order. The flat ribbons were 30−90 nm (8− 22 QDs) wide based on AFM and TEM, about 8−18 nm (2−5 QDs) high based on AFM, and 0.5−10 μm long based on SEM. Passivation of defect sites, likely by S, enhanced the photoluminescence of the ribbons relative to the raw QDs. Multibranched clusters containing fused dots formed in IPA as well as ribbons with pendent nodules. The photoluminescence of the assortment was attenuated compared to the raw QDs. Injecting into acetone not only yielded ribbons and clusters but also dissolved the dots over a period of 20 days, forming flower-like assemblies whose petals consisted of bundles of CdS wires. Diluting in solvents with lower dielectric constants than water initially aggregated the dots by reducing the electrostatic screening between the negatively charged thioglycolic acid (TGA) ligand layers. The solubility of TGA in the solvents determined the superstructure that formed. Extracting the smallest portion of this layer in methanol promoted vectorial growth into ribbons consistent with dipole−dipole attractive and charge−charge repulsive interactions. Removing more of the TGA layer in IPA caused the dots to fuse into webs containing clustered ribbons and branches, and the directional nature of the superstructure was lost. Completely deprotecting the surface in acetone promoted photoetching and dissolved the dots. Control of the ligand surface density by means of the solubility adds another method to direct spontaneous self-organization of QDs.

show abstract

Section: Results and Discussionsupporting

confidence: 58%

Solvent-Triggered Self-Assembly of CdTe Quantum Dots into Flat Ribbons

Jiang

Muscat

2013

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…Procedure for synthesis of water soluble CdSe NPs was adapted from the protocols described by Gaponik et al [28] and Chen et al [29]. In a typical synthesis 0.5 mL of 1.0 M CdCl 2 solution and 0.5 mL of thioglycolic acid (HSCH 2 COOH) as capping agent were added to 250 mL deionized water in a three-neck flask under stirring.…”

Section: Methodsmentioning

confidence: 99%

Probing metabolic stability of CdSe nanoparticles: Alkaline extraction of free cadmium from liver and kidney samples of rats exposed to CdSe nanoparticles

Arslan

Ateş

McDuffy

et al. 2011

Journal of Hazardous Materials

View full text Add to dashboard Cite

Cadmium selenide nanoparticles (CdSe NPs) exhibit novel optoelectronic properties for potential biomedical applications. However, their metabolic stability is not fully understood because of the difficulties in measurement of free Cd from biological tissues of exposed individuals. In this study, alkaline dissolution with tetramethylammonium hydroxide (TMAH) is demonstrated for selective determination of free Cd and intact NPs from liver and kidney samples of animals that were exposed to thiol-capped CdSe NPs. Aqueous suspensions of CdSe NPs (3.2 nm) were used to optimize the conditions for extracting free Cd without affecting NPs. Nanoparticles were found to aggregate when heated in TMAH without releasing any significant Cd to solution. Performance of the method in discriminating free Cd and intact NPs were verified by Dogfish Liver (DOLT-4) certified reference material. The samples from the animals were digested in 4 mL TMAH at 70 °C to extract free Cd followed by analysis of aqueous phase by ICP-MS. Both liver and kidney contained significant levels of free Cd. Total Cd was higher in the liver, while kidney accumulated mostly free Cd such that up to 47.9% of total Cd in the kidney was free Cd when NPs were exposed to UV-light before injection.

show abstract

“…[77][78][79] Thiol group containing amino acids have proved to be excellent stabilizers, with Lcysteine becoming one of the most popular surface capping molecules for CdX (X ¼ S, Se, Te) nanoparticles. 67,[80][81][82][83][84][85][86] Recently the use of stereospecific chiral stabilizing molecules opened another avenue of interest in the area of quantum dot research, as chirality is a key factor in biological and biochemical interactions. However this is a very new area.…”

Section: Chiral Semiconductor Quantum Dots (Qds)mentioning

confidence: 99%