Light amplification in semiconductor nanocrystals: Quantum rods versus quantum dots

2003 ◽  
Vol 82 (26) ◽  
pp. 4776-4778 ◽  
Author(s):  
H. Htoon ◽  
J. A. Hollingworth ◽  
A. V. Malko ◽  
R. Dickerson ◽  
V. I. Klimov
Keyword(s):  
Quantum Dots ◽  
Semiconductor Nanocrystals ◽  
Quantum Rods ◽  
Light Amplification

Application of quantum dots in drug delivery

2021 ◽  
Vol 11 ◽  
Author(s):  
Subham Jain N ◽  
Preeti S ◽  
Amit B Patil
Keyword(s):  
Drug Delivery ◽  
Quantum Dots ◽  
Organic Dyes ◽  
Quantum Confinement Effect ◽  
Semiconductor Nanocrystals ◽  
Drug Carriers ◽  
Research Field ◽  
The Body ◽  
Future Application ◽  
Potential Candidate

Background: The nanotechnology which has vast growth in the research field and the outcome product of nanotechnology is nanoparticles. Quantum dots with a size range of 2-10nm represents a new form in nanotechnology materials. It has showed widespread attention in recent years in the field of science and its application in drug delivery. Quantum dots are semiconductor nanocrystals which possess interesting properties and characteristics such as unique optical properties, quantum confinement effect and emit fluorescence on excitation with a light source which makes them a potential candidate for nano-probes and for carriers for biological application. Objective: The objective of the article is to explain the role and application of Quantum dots in drug delivery and its future application in pharmaceutical science and research. This review focuses on drug delivery through Quantum dots and Quantum dots helping nanocarriers for drug delivery. The development of QD nano-carriers for drugs has become a hotspot in the fields of nano-drug research. The Quantum Dot labelled nano-carrier can able to deliver the drugs with fewer side effects and it can able to trace the drug location in the body. Results: The Fluorescent emission of Quantum dots is better than other organic dyes which leads to better drug delivery for cancer or acting as a tag for other drug carriers. Conclusion: Because of emission property of Quantum Dots, it can be said used with other drug carriers and later it can be traced with the help of Quantum Dots. Quantum dots can be said as smart Drug delivery.

scholarly journals Synthesis, Properties and Bioimaging Applications of Silver-Based Quantum Dots

2021 ◽  
Vol 22 (22) ◽  
pp. 12202
Author(s):  
Mariya Borovaya ◽  
Inna Horiunova ◽  
Svitlana Plokhovska ◽  
Nadia Pushkarova ◽  
Yaroslav Blume ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Near Infrared ◽  
Semiconductor Nanocrystals ◽  
Current Status ◽  
Synthesis Properties ◽  
Semiconductor Nanomaterials ◽  
Electrooptical Properties ◽  
Basic Features

Ag-based quantum dots (QDs) are semiconductor nanomaterials with exclusive electrooptical properties ideally adaptable for various biotechnological, chemical, and medical applications. Silver-based semiconductor nanocrystals have developed rapidly over the past decades. They have become a promising luminescent functional material for in vivo and in vitro fluorescent studies due to their ability to emit at the near-infrared (NIR) wavelength. In this review, we discuss the basic features of Ag-based QDs, the current status of classic (chemical) and novel methods (“green” synthesis) used to produce these QDs. Additionally, the advantages of using such organisms as bacteria, actinomycetes, fungi, algae, and plants for silver-based QDs biosynthesis have been discussed. The application of silver-based QDs as fluorophores for bioimaging application due to their fluorescence intensity, high quantum yield, fluorescent stability, and resistance to photobleaching has also been reviewed.

scholarly journals Tunable Quantum Photoinitiators for Radical Photopolymerization

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2694
Author(s):  
Shubhangi Shukla ◽  
Prem C. Pandey ◽  
Roger J. Narayan
Keyword(s):  
Quantum Dots ◽  
Metal Oxides ◽  
Radical Polymerization ◽  
Mechanism Of Action ◽  
Carbon Dots ◽  
Semiconductor Nanocrystals ◽  
Metal Sulfides ◽  
Cross Linking ◽  
Reversible Deactivation ◽  
Reversible Deactivation Radical Polymerization

This review describes the use of nanocrystal-based photocatalysts as quantum photoinitiators, including semiconductor nanocrystals (e.g., metal oxides, metal sulfides, quantum dots), carbon dots, graphene-based nanohybrids, plasmonic nanocomposites with organic photoinitiators, and tunable upconverting nanocomposites. The optoelectronic properties, cross-linking behavior, and mechanism of action of quantum photoinitiators are considered. The challenges and prospects associated with the use of quantum photoinitiators for processes such as radical polymerization, reversible deactivation radical polymerization, and photoinduced atom transfer radical polymerization are reviewed. Due to their unique capabilities, we forsee a growing role for quantum photoinitiators over the coming years.

Solution NMR Spectroscopy as a Useful Tool to Investigate Colloidal Nanocrystal Dispersions from the Capping Ligand's Point of View

2006 ◽  
Vol 984 ◽  
Author(s):  
Jose C Martins ◽  
Jose C Martins ◽  
Iwan Moreels ◽  
Zeger Hens
Keyword(s):  
Quantum Dots ◽  
Free Energy ◽  
Field Gradient ◽  
Dynamic Equilibrium ◽  
Semiconductor Nanocrystals ◽  
Point Of View ◽  
Solution Nmr ◽  
Free Energy Of Adsorption ◽  
Ligand Interaction ◽  
Pulsed Field

AbstractColloidal semiconductor nanocrystals or quantum dots are an important building block in bottom-up nanotechnology. They consist of an inorganic, crystalline core surrounded by a monolayer of organic ligands. As these ligands can be modified or exchanged for others, they provide a convenient way to give the quantum dots functionality. Here, we show that solution NMR techniques, including diffusion pulsed field gradient spectroscopy, is a very useful tool to investigate the ligands of colloidal nanocrystals. This is demonstrated using InP quantum dots with trioctylphospine oxide ligands as an example. Combining 1H-13C HSQC spectroscopy with pulsed field gradient diffusion NMR, an unequivocal identification of the resonances of the bound ligands is possible. This leads to the determination of the diffusion coefficient of the nanocrystals in solution and allows to verify capping exchange procedures. By calibrating the surface area of the NMR resonances using a solute of known concentration, the density of ligands at the nanocrystal surface can be quantified. We could demonstrate that a dynamic equilibrium exists between bound and free ligands. Analysis of the corresponding adsorption isotherm - determined using 1H NMR - leads to an estimation of the free energy of adsorption and the free energy of ligand-ligand interaction at the nanocrystals surface. Similar investigations are in progress on capped PbSe and ZnO2 nanoparticles. Preliminary results strongly support the generic nature of the approach described for the case of TOPO capped InP nanocrystals.

A facile non-injection phosphorus-free synthesis of semiconductor nanoparticles using new selenium precursors

CrystEngComm ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 786-793
Author(s):  
Maksym Prodanov ◽  
Maksym Diakov ◽  
Valerii Vashchenko
Keyword(s):  
Quantum Dots ◽  
Semiconductor Nanoparticles ◽  
Quantum Rods ◽  
Luminescent Quantum Dots

New Se-precursors enable the phosphorus-free non-injection synthesis of luminescent quantum dots and nanotetrapods as well as the injection-based synthesis of quantum rods.

Modeling of the formation kinetics and size distribution evolution of II–VI quantum dots

2017 ◽  
Vol 2 (4) ◽  
pp. 567-576 ◽  
Author(s):  
Stefano Lazzari ◽  
Milad Abolhasani ◽  
Klavs F. Jensen
Keyword(s):  
Quantum Dots ◽  
Size Distribution ◽  
Semiconductor Nanocrystals ◽  
Population Balance ◽  
Nanocrystal Size ◽  
Balance Model ◽  
Population Balance Model ◽  
Formation Kinetics

A population balance model describes the formation of II–VI semiconductor nanocrystals and predicts experimentally observed properties of the nanocrystal size distribution.

Synthesis and Characterization of III-V Rod Shape Semiconductor Nanocrystals

2005 ◽  
Vol 494 ◽  
pp. 121-128
Author(s):  
J.M. Nedeljković ◽  
O.I. Mićić ◽  
S.P. Ahrenkiel ◽  
A.J. Nozik
Keyword(s):  
Size Distribution ◽  
Semiconductor Nanocrystals ◽  
Synthesis And Characterization ◽  
Lateral Growth ◽  
Narrow Size Distribution ◽  
Free Standing ◽  
Quantum Rods ◽  
Metallic Catalyst ◽  
Strong Confinement

InP and InAs quantum rods were synthesized via the reactions of monodispersed indium droplets with phosphide or arsenide ions, respectively. In these reactions indium droplets, which do not act as a catalyst but rather as a reactant, are completely consumed. For the synthesis of InP and InAs quantum rods with a narrow size distribution, a narrow size distribution of indium particles is required because each indium droplet serves as a template to strictly limit the lateral growth of individual InP or InAs nanocrystals. Free-standing InP (130 Å diameter and 870 Å length) and InAs (180 Å diameter and 745 Å length) quantum rods without residual metallic catalyst at the rod tip were synthesized from the diluted transparent solutions of metallic indium. Both kinds of synthesized nanorods are in the strong confinement regime since the Bohr diameters of InP and InAs are 200 and 700 Å, respectively.

The Cytotoxicity of Quantum Dots CdSe/CdS functionalized with -COOH and –NH2

2009 ◽  
Vol 1220 ◽  
Author(s):  
Lin-Jing Shen ◽  
Jing Cui ◽  
Jin-Hua Liu ◽  
Xiao-Bo Xu ◽  
Ming-Qiang Zhu
Keyword(s):  
Quantum Dots ◽  
Fluorescent Dyes ◽  
Semiconductor Nanocrystals ◽  
Assay Method ◽  
Dependent Effect ◽  
Lower Toxicity ◽  
Size Dependent ◽  
Dose Dependent ◽  
Dose Dependent Effect ◽  
Mtt Assays

AbstractRecently, semiconductor nanocrystals or quantum dots (QDs) aroused great concern because of their unique properties such as the size-dependent photoluminescence. They have many excellent applications in areas of molecular bioimaging, medical detection and even energy, especially as biosensing and imaging instead of fluorescent dyes. For the bio-safety, however, we should assess the cytotoxicity of QDs before used in biomedical imaging. Here, the cytotoxicity of amino-functionalized CdSe/CdS (CdSe/CdS-NH2) QDs and carboxy-functionalized CdSe/CdS (CdSe/CdS-COOH) QDs was investigated by MTT assay method. According to our findings, both CdSe/CdS-NH2 and CdSe/CdS-COOH have a dose-dependent effect on cell proliferation. The cytotoxicity of QDs varies with storing time of QDs and kinds of cells. The cytotoxicity of QDs modified with -COOH or -NH2 groups both vary with concentrations in positive linear or change with QD storing time in negative linear. The results indicate that CdSe/CdS-COOH QDs have lower toxicity than CdSe/CdS-NH2 QDs. Hela cell is somewhat more sensitive to amino- and carboxy-modified QDs than Bel7404 cell for MTT assays.

scholarly journals Core-shell Semiconductor Nanocrystals: Effect of Composition, Size, Surface Coatings on their Optical Properties, Toxicity and Pharmacokinetics

2017 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Wafa' T. Al-Jamal
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Photodynamic Therapy ◽  
Biomedical Applications ◽  
Semiconductor Nanocrystals ◽  
Organic Dye ◽  
Surface Coatings ◽  
Core Shell ◽  
Biomedical Field

Quantum dots are semiconducting nanocrystals that exhibit extraordinary optical properties. QD have shown higher photostability compared to standard organic dye type probes. Therefore, they have been heavily explored in the biomedical field. This review will discuss the different approaches to synthesis, solubilise and functionalise QD. Their main biomedical applications in imaging and photodynamic therapy will be highlighted. Finally, QD biodistribution profile and in vivo toxicity will be discussed.

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