Simple Syntheses of CdSe Quantum Dots
Transfer the octadecene CdSe quantum dot suspension to a micro centrifuge tube. Add 100% ethanol. Cap.
CdSe Quantum Dots synthesis - YouTube
Quantum dots are an excellent resource for demonstrating quantum phenomena. Two new methods for synthesizing quantum dots are presented. Proceeding at relatively low reaction temperatures, these exercises are safe and easy to conduct in an undergraduate student laboratory. The quantum dots prepared from the first method exhibited visible luminescence across a broad range of colors. The size-dependent spectral properties of quantum dots were examined quantitatively in the second method. Following this procedure, students in an advanced chemistry laboratory course synthesized their own quantum dots and gained experience with these important nanomaterials.
46. Dorfs D, Krahne R, Falqui A, Manna L, Giannini C, Zanchet D. Quantum Dots: Synthesis and Characterization. In: (ed.) David LA, Gregory DS, Gary PW. Amsterdam: Academic Press. 2011:219-70
CdSe Quantum Dot Synthesis - YouTube
Use of microwave radiation to speed up the synthesis of CdSe-based quantum dots (QDs) in aqueous media is of practical interest and is the focus of this study. However, such microwave methods usually lead to low quantum yield (QY) QDs as compared to the conventional organic-based synthesis. By coupling the microwave oven with a fluorometer via a fiber optic cable, the fluorescence spectra during the QD evolution were obtained. Using the composition Cd4:Se1:Zn4:MPA20 (MPA = 3-mercaptopropionic acid), several stages of QD growth including development of CdSe nuclei, followed sequentially by CdS and then ZnS deposition were noted. The temperature of the microwave reaction between 130 and 155 °C led to QDs with similar QYs (17–19%), with the lower temperature taking longer to reach the optimal yield. The nucleation step was carried out at temperatures varying from 0 to 100 °C followed by growth in the microwave oven. With increasing temperature of nucleation, there was a red-shift in emission maximum, varying from 549 to 574 nm, with comparable QY, thus providing a route for QD size control in the microwave process. There was a profound effect of light illumination on the nucleated state prior to microwave treatment. Using light illumination, QDs with a QY of 40–41% were reproducibly obtained. With such optimized QDs, both flow cytometry and confocal microscopy of QD uptake into intestinal epithelial cells at 0.8–8 nM concentration were readily observed.
Experimental chemistry is not our forte, so we prefer to use professionally-manufactured quantum dots for the Schrödinger’s Wave Equation experiments we discuss in the ‘s Chapter 7. However, if you are interested in synthesizing your own quantum-dot nanoparticle suspensions, we recommend that you take a look at the detailed instructions prepared by Professor George Lisensky at Beloit College for the (Local printer-friendly copy at: ).
An alternative method of quantum dot synthesis, ..
MMP-9 gene silencing in BMVEC by QD-siRNAMMP-9 nanoplexes: BMVECs were transfected with QD-siRNAMMP-9 or Xtreme-siRNAMMP-9 or Xtreme siRNAscrambled for 48 h. RNA was extracted, reverse transcribed, cDNA amplified and MMP-9 gene expression was determined by real-time, quantitative PCR. Relative expression of mRNA species was calculated using the comparative CT method. Data are the mean ± SD of 3 separate experiments done in duplicate. Statistical significance was determined using ANOVA based comparing QD-siRNAMMP-9 nanoplexes to the negative control samples. Reprinted from Brain Research, 1282, Adela Bonoiu, Supriya D. Mahajan, Ling Ye, Rajiv Kumar, Hong Ding, Ken-Tye Yong, Indrajit Roy, Ravikumar Aalinkeel, Bindukumar Nair, Jessica L. Reynolds, Donald E. Sykes, Marco A. Imperiale, Earl J. Bergey, Stanley A. Schwartz, Paras N. Prasad, gene silencing by a quantum dot-siRNA nanoplex delivery to maintain the integrity of the blood brain barrier, 142-155, Copyright (2009), with permission from Elsevier.
Wu et al. reported polysaccharide-based hybrid nanogels that combine functional building blocks for optical pH-sensing, cancer cell imaging, and controlled drug release within a single nanoparticle system for combined diagnosis and therapy. The hybrid nanogels were synthesized by in-situ immobilization of CdSe QDs in the interior of the dual responsive (pH and temperature) hydroxypropylcellulose -poly (acrylic acid) (HPC-PAA) semi-interpenetrating polymer networks. The HPC-PAA-CdSe hybrid nanogels combine a strong trap emission at 741 nm for sensing physicochemical environment in a pH dependent manner and a visible excitonic emission at 592 nm for mouse melanoma B16F10 cell imaging. The hybrid nanogels also provide excellent stability as a drug carrier. They not only provide a high drug loading capacity for a model anticancer drug, temozolomide, but also offer a pH-triggered sustained-release of the drug molecules in the gel network.
Synthesis of CdSe/ZnS and CdTe/ZnS Quantum Dots: …
Synthesis of Cadmium Selenide Quantum Dot Nanoparticles
04/01/2011 · Synthesis of CdSe Quantum Dot Nanoparticles - Duration: 6:43
‘Giant’ CdSe/CdS Core/Shell Nanocrystal Quantum Dots …
04/11/2011 · We report synthesis of CdSe and CdTe quantum dots ..
CdSe ZnS Quantum Dots Highly Pure Quality Lowest Price
‘Giant’ CdSe/CdS Core/Shell Nanocrystal Quantum Dots As Efficient Electroluminescent Materials: Strong Influence of …
Koposov, A.Y., et al., CdSe Quantum-Dot ..
1. Engineering a biosensor for detection of quantum dots Supervisor: Evamaria Petersen and Peter Fojan The toxic heavy metals cadmium and lead are naturally occurring elements in the environment. Due to their unique chemical and physical properties like resistance to corrosion, excellent electrical conductivity and low melting point, these metals have several widespread applications in a number of industries. Cadmium for instance has been used in Ni Cd batteries, paints, metal plating, stabilizers, alloys, and electronic compounds such as cadmium telluride (CdTe). Excellent properties such as bright coloring (quantum dots), resistance to detergents and other corrosive chemicals, water-insolubility, and heat stability makes cadmium pigments essential in the manufacture of plastics, ceramics, colors and enamels. However, harmful effects are associated with these metal ions. These metals are prevalent in the environment and are toxic even at low levels. Chronic exposure to lead in humans can lead to anemia, neurotoxicity, and renal damage, and can be fatal in some cases. The most common effects of cadmium exposure are kidney disease, lung damage, fragile bones, and abdominal pain. One feature of the toxicity associated with these metals is their tendency to accumulate in the body over an extended period of time that eventually can lead to long-term effects in humans. Extensive industrial demand and other environmental sources make these pollutants a serious health concern. Therefore, it is important to monitor the presence of these metal ions in the environment and prevent the excessive exposure of various life forms to these metals. Monitoring of most metal ions present in environmental samples is carried out using conventional analytical techniques, such as inductively coupled plasma-atomic emission/mass spectroscopy (ICP/AES, ICP/MS), or electrochemically by anodic stripping voltammetry (ASV).
One pot synthesis of bi-linker stabilised CdSe quantum dots
Quantum dots (QDs) are luminescent nanocrystals with rich surface chemistry and unique optical properties that make them useful as probes or carriers for traceable targeted delivery and therapy applications. QDs can be functionalized to target specific cells or tissues by conjugating them with targeting ligands. Recent advancement in making biocompatible QD formulations has made these nanocrystals suitable for applications. This review provides an overview of the preparation of QDs and their use as probes or carriers for traceable, targeted therapy of diseases and . More specifically, recent advances in the integration of QDs with drug formulations for therapy and their potential toxicity and are highlighted. The current findings and challenges for optimizing QD/drug formulations with respect to optimal size and stability, short-term and long-term toxicity, and applications are described. Lastly, we attempt to predict key trends in QD/drug formulation development over the next few years and highlight areas of therapy where their use may provide breakthrough results in the near future.
Isolation of CdSe Quantum Dot Nanoparticles
In this laboratory, students will study how surfactant-based chemistry can be used to synthesize CdSe quantum dots and study how the size of the quantum dots can be controlled by varying reaction time. The laboratory will demonstrate how the color of these quantum dots can be connected to the size of the nanoparticle by considering the electrons as freely moving particles in a box with the dimensions of the nanoparticle. The model of will be compared with more exact results, and use this to create a calibration curve. Students will be able to estimate the size of quantum dots by using UV-VIS absorption spectroscopy
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