luminescent quantum dots as advanced biological labels

... quenched phosphorescence signal increased with increasing pH, was stable between pH 7.4 and 8.0, and decreased sharply afterwards (Figure 2) Thus pH 7.4 was selected as the optimum value 2.3 Reaction ... suspension that formed was sonicated for 9 min in an ultrasonic bath After extraction, 50 mL of this suspension was withdrawn, extracted twice with 20 mL of ether, and the aqueous phase was collected These ... interference In addition, electrochemical techniques based on an enzymatic assay also have some disadvantages, such as instability of enzymes, decrease in their catalytic activity, and difficulty of

Ngày tải lên: 13/01/2022, 00:09

... High-power InGaAs/GaAs Quantum Qot Lasers Appl Phys Lett 2001, 78:1207. 48 Huffaker DL, Park G, Zou Z, Shchekin OB, Deppe DG: 1.3 μm Room-temperature GaAs-based Quantum-dot Laser Appl Phys Lett ... Stranski-Krastanov GaN/AlN Quantum Dots Grown by Metal Organic Vapor Phase Epitaxy J Appl Phys 2006, 99:083509. 44 Ee YK, Zhao H, Arif RA, Jamil M, Tansu N: Self-Assembled InGaN Quantum Dots on ... Pre-structured GaAs Surfaces for Subsequent Site-selective InAs Quantum Dot Growth Nanoscale Res Lett 2011, 6:211. 52 Yeoh TS, Swint RB, Gaur A, Elarde VC, Coleman JJ: Selective Growth of InAs Quantum Dots

Ngày tải lên: 21/06/2014, 04:20

... when W(001) was maintained as the constant value of 150 nm As shown in Figure 4a,b,c,d, the intensities of the first peaks saturated as the excitation power of laser increased, whereas the intensities ... Single PL peak was occurred for In0.8Ga0.2As SAQDs grown on SiO2-patterned exact (001) GaAs, whereas double PL peaks were showed for SAQDs grown on 5°-off (001) GaAs substrates as the width of ... In0.8Ga0.2As SAQDs selectively grown by utilizing SiO2-patterned 5°-off (001) GaAs substrates have well-defined zero-dimensional quantum states Trang 3Introduction Self-assembled quantum dots (SAQDs)

Ngày tải lên: 21/06/2014, 17:20

... self-assembled layers of CdS quantum dots Chem 9 Lin SC, Lee YL, Chang CH, Shen YJ, Yang YM: Quantum-dot-sensitized solar cells: assembly of CdS-quantum-dots coupling techniques of self-assembled ... deposition [CBD] method When PbS was introduced as the QD sensitizer, a cascade energy alignment was formed in the hybrid solar cell, and a ηP as high as 0.42% was achieved Experimental section ... When the CBD cycles further increases, JSC decreases The decrease of JSC with the increasing CBD cycles is considerably attributed to two reasons: one is the decrease of ZnO amount due to the growth

Ngày tải lên: 21/06/2014, 17:20

... electrical properties due to quantum confinement, hence their commonly used name of quantum dots [13,14] QDs have many desirable properties for biological imaging, such as high quantum yields, high molar ... Nanotechnology has the potential to profoundly transform the nature of cancer diagnosis and cancer patient management in the future Over the past decade, quantum dots (QDs) have become one of the fastest ... involved in the pathology of diseases such as cancer Since the first dem-onstration of the biomedical potential of QDs in 1998 [1, 2], QD-based research has increased exponentially in re-cent years

Ngày tải lên: 22/06/2014, 18:20

... to cope with the tasks of the decades to come Stranski-Krastanow Quantum Dot Gain Media Lasing in self-organized Stranski-Krastanow QDs (SK-QDs) at room and low temperatures was reported in 1993 ... first-ever GaAs-based VCSEL emitting beyond 1.3 lm was realized using SK InAs QDs [15] There has been a lot of activities to improve the device However, in spite of the fact that the basic performance ... Keywords Quantum dots Nanophotonics  Semiconductor lasers Surface-emitting lasers  Self-organized growth Introduction Presently, data traffic crossing optical fiber networks increases three

Ngày tải lên: 22/06/2014, 18:20

... by InAs/ GaAs(001) QDs QDs are buried with a thin GaAs layer and then an in situ etching step is applied AsBr3 gas is used as etchant The strain modulation from the buried InAs QDs increases ... self-assembled QDs are widely used as a playground to study novel physical phenomena such as cavity quantum electro-dynamics [3, 4], as well as building blocks for high performance QD-based devices ... Heisenbergstrasse 1, D-70569 Stuttgart, Germany e-mail: s.kiravittaya@fkf.mpg.de DOI 10.1007/s11671-006-9014-8 N A N O R E V I E W Multi-scale ordering of self-assembled InAs/GaAs(001) quantum dots S

Ngày tải lên: 22/06/2014, 22:20

... Trang 35Optics and LASER Trang 37Capping of InAs/GaAs Quantum Dots for GaAs Based Lasers This chapter is concentrated on quantum dots, which are prepared with the aim to become a base for low cost, ... for laser design Fig 2 Atomic force microscopy images of a) uncapped lens shaped InAs quantum dots on GaAs substrate with the circular base b) InAs dots after capping by 10 nm of GaAs, dots are ... InAs/GaAs quantum dot layer determine such parameters as density, homogeneity and original size of quantum dots However, the final properties of quantum dots are significantly determined by quantum

Ngày tải lên: 26/06/2014, 23:20

... small quantum dots Here the emphasis lies on the electron spin to be used as a qubit The experimental steps toward using a single electron spin –trapped in a semiconductor quantum dot – as a spin ... quantum algorithm, as well as microscopic systems such as atoms or ions have excellent coherence properties,but are not easily accessible or scalable – on the other hand, larger systemssuch as ... Few-Electron Quantum Dots as Spin Qubits 82 References 92 Low-Temperature Conduction of a Quantum Dot M Pustilnik and L.I Glazman 97 1 Introduction 97 2 Model of a Lateral Quantum Dot

Ngày tải lên: 27/06/2014, 10:20

... cluster of quantum dots This kind of model can be very helpful for evaluating phenomena like 3-D shape changes due to damage caused by quantum dots, and the 3-D distribu-tions of the quantum dots themselves ... purposes, absolute accuracy is not as important as consistency, as when comparing the sizes of one popu-lation of structures with those of another popupopu-lation As long as the imaging parameters are ... morphological and biochemical changes with physiological outcomes 1 Background Quantum dots (QDs) are increasingly being used as a complement to molecular dyes in bio-imaging applica-tions Compared

Ngày tải lên: 11/08/2014, 00:22

... electrophoresis coupled with laser-induced fluorescence was used for the characterization of quantum dots and their conjugates to biological molecules The CE-LIF was laboratory-built and capable ... Background Quantum dots (QDs) are fluorescent nanoparticles that receive increasing recognition as a viable alternative (to conventional organic fluorophores) for molecular labe-ling Their quantum ... acid-functionalized quantum dots Selective techniques involved 1) the use of heterobifunctional crosslinker, sulfo-SMCC, for the conjugation of partially reduced IgG to amine-functionalized quantum dots, and

Ngày tải lên: 11/08/2014, 00:22

... Only when D5 dendrons were used as the intervening linkage, was the water solubility sufficient to measure a Ki value Also, it was necessary to exhaustively wash the QD derivatives Figure 5 Synthesis ... conjugate The issue of internal quenching, as observed from dopamine conjugates of QDs [24], has also been explored Results This study was designed to probe the feasibility of bind-ing QDs to the human ... make useful affinity probes Background Quantum dots (QDs) are crystalline semiconducting nanoparticles that, when properly derivatized, are com-patible with biological systems to provide a chemically

Ngày tải lên: 11/08/2014, 00:22

... was settled for the assessment of the impact of the addition of mercaptopropanoic acid coated CdSe/ZnS QDs Cell growth was significantly reduced when 100 mM of mercaptopropanoic acid -QDs was ... Chlamydomonas reinhardtii, in which the toxicity of two types of widely used nanomaterials (TiO2 and CdTe) was evaluated [7] No data is available concerning toxicology of Quantum Dots (QDs) in ... core-shell CdSe/ZnS QDs, the cores obtained were monodisperse after passivation with at least monolayers of ZnS Passivation was obtained using the SILAR method [12] that consists of alternating

Ngày tải lên: 11/08/2014, 00:22

... uncon-jugated QDs as shown in Figure 6, as well as due to gradual loss of both the intein peptide and the target protein from the QD surface, as a result of proteolytic degradation, as discussed in ... excess This was expected in the case of paxil-lin, a cytosolic protein occasionally localized to the focal adhesion complexes on the cell membrane, but came as a surprise in the case of memEGFP, ... real time revealed that QDs would associate with newly formed focal adhesions and would be released once the complexes were disassembled Finally, split intein based QD conjugation may be extended

Ngày tải lên: 11/08/2014, 00:23

... Furthermore, the CAM has been used as an alternative to the Draize test for irritancy assessment The vascularity and easy access to the CAM would allow it to be used in vasoactive studies, whereby ... al., 2009) As the CAM is thin and transparent, the highly vascular structures located within can be easily seen Hence, it was employed in vasoreactivity studies (Dunn et al., 2005) The vascularity ... successful as a buccal model, the CAM could be used to evaluate the biological absorption of vasoactive drugs by measuring blood perfusion The highly vascularised nature of the CAM allows for the assessment

Ngày tải lên: 11/09/2015, 10:00

... (PL) as well as broad and intense absorption of luminescent semiconductor QDs have attracted tremendous attention in the last decade for their potential application as biomedical imaging labels, ... PL measurements with femtosecond laser pulses at 1000 nm, which is close to a semi-transparent window for many biological specimens The 3PA cross-section is as Trang 8below-band-edge PL has a ... called quantum confinement effect, which was discovered by Jain and Lind in 1983 [1.7] To give a clear understanding of the nonlinear mechanisms and ultrafast carrier dynamics as well as their

Ngày tải lên: 11/09/2015, 10:06

... semiconductor quantum dots Ⅱ-Ⅵ wide band-gap semiconductors quantum dots (QDs), such as CdSe and ZnSe, have attracted much attention Their optical properties make them suitable as visible light ... 2.4 Quantum model of Raman scattering In quantum theory, Raman scattering is considered as an inelastic collision process in which a quantum of the incident radiation is annihilated or a quantum ... frequency A compressive strain (as high as 3.5 GPa) was induced in graphene by depositing a 5 nm SiO2 followed by annealing, whereas a tensile strain (~ 1 GPa) was obtained by depositing a thin

Ngày tải lên: 13/09/2015, 21:36

... Trang 12the Quantum Dots in aqueous solution The dashed curves are the theoretical fits Quantum Dots measured with 120-fs laser pulses at 780-nm wavelength at different intensities The dashed curve ... GSH-capped CdSe Quantum Dots The solid and dashed curves are the theoretical results Quantum Dots measured with 120-fs laser pulses at 780-nm wavelength The relaxation processes measured at various ... of quantum dots As mentioned in the last section, semiconductor materials confined in one, two and three dimensions in the nano-scale are called quantum wells, quantum wires and quantum dots,

Ngày tải lên: 14/09/2015, 08:38

... synthesis were purchased from Sigma-Aldrich Al2Te3 was purchased from Cerac Inc AlamarBlue was purchased from Biosource International A BrdU cell proliferation kit was purchased from Roche Diagnostics ... Howarth M, Takao K, Hayashi Y, Ting AY: Targeting quantum dots to surface proteins in living cells with biotin ligase PNAS 2005, 102:7583-7588 30 Sundara Rajan S, Vu TQ: Quantum Dots Monitor TrkA ... acquisition was also used to acquire three colour images Rhodamine phalloidin was excited using the HeNe1 543 nm laser and the emitted fluorescence was acquired at 575 nm DAPI stain was excited with laser...

Ngày tải lên: 11/08/2014, 00:22

... 6(2), (2006) Multicolor quantum dots for molecular diagnostics www future-drugs.com 1.2 Time (min) quantum dots 15 10 20 25 30 35 Intensity (au) Quantum dots 0.8 0.6 0.4 0.2 Texas red 0 20 40 60 80 ... nanoparticle that has the potential to be used as a sensitive probe for screening cancer markers in fluids, as a specific label for classifying tissue biopsies, and as a high-resolution contrast agent ... accurately assess invasive potential of different cancer cell types, as motility of cells is strongly associated with their malignancy in vivo This new assay could aid in the clinical classification...

Ngày tải lên: 15/02/2014, 05:20