Synthesis and Optical Properties of Thiol Functionalized CdSe/ZnS (Core/Shell) Quantum Dots by Ligand Exchange

The colloidal photoluminescent quantum dots (QDs) of CdSe (core) and CdSe/ZnS (core/shell) were synthesized at different temperatures with different growth periods. Optical properties (i.e., UV/Vis spectra and photoluminescent emission spectra) of the resulting QDs were investigated. The shell-protected CdSe/ZnS QDs exhibited higher photoluminescent (PL) efficiency and stability than their corresponding CdSe core QDs. Ligand exchange with various thiol molecules was performed to replace the initial surface passivation ligands, that is, trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP), and the optical properties of the surface-modified QDs were studied. The thiol ligand molecules in this study included 1,4-benzenedimethanethiol, 1,16-hexadecanedithiol, 1,11-undecanedithiol, biphenyl-4,4′-dithiol, 11-mercapto-1-undecanol, and 1,8-octanedithiol. After the thiol functionalization, the CdSe/ZnS QDs exhibited significantly enhanced PL efficiency and storage stability. Besides surface passivation effect, such enhanced performance of thiol-functionalized QDs could be due to cross-linked assembly formation of dimer/trimer clusters, in which QDs are linked by dithiol molecules. Furthermore, effects of ligand concentration, type of ligand, and heating on the thiol stabilization of QDs were also discussed.

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The shell thickness and surface passivation dependence of fluorescence decay kinetics in CdSe/ZnS core-shell and CdSe core colloidal quantum dots

Journal of Luminescence ◽

10.1016/j.jlumin.2017.08.024 ◽

2017 ◽

Vol 192 ◽

pp. 860-866 ◽

Cited By ~ 5

Author(s):

Ruwini D. Rajapaksha ◽

Mahinda I. Ranasinghe

Keyword(s):

Quantum Dots ◽

Shell Thickness ◽

Surface Passivation ◽

Fluorescence Decay ◽

Colloidal Quantum Dots ◽

Core Shell ◽

Decay Kinetics ◽

Cdse Core ◽

Fluorescence Decay Kinetics

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Conjugation ofE. coliO157:H7 Antibody to CdSe/ZnS Quantum Dots

Journal of Nanomaterials ◽

10.1155/2015/265315 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 12

Author(s):

N. T. Vo ◽

H. D. Ngo ◽

D. L. Vu ◽

A. P. Duong ◽

Q. V. Lam

Keyword(s):

Quantum Dots ◽

Shell Structure ◽

Trioctylphosphine Oxide ◽

Core Shell ◽

Cdse Core ◽

Green Method ◽

Potential Measurement ◽

E Coli ◽

Luminescence Efficiency ◽

Core Shell Structure

The conjugation of antibody to semiconductor quantum dots plays a very important role in many applications such as bioimaging, biomarking, and biosensing. In this research, we present some results of highly luminescent core/shell structure CdSe/ZnS on which theE. coliantibody was conjugated. The CdSe core was synthesized successfully with chemical “green” method. For biological applications, the capping surfactant, trioctylphosphine oxide, was substituted by a new one, mercaptopropionic acid (MPA), before the antibody attachment step. Finally, theE. coliantibody was attached to quantum dots CdSe/ZnS. Morphology, structure, and optical properties were investigated with PL, UV-Vis, TEM, and XRD methods. The successful ligand substitution and antibody attachment were confirmed by zeta potential measurement, FTIR spectroscopy, and TEM. The results showed quantum dots size of 2.3 nm, uniform distribution, and high luminescence. CdSe/ZnS core/shell structure had better stability and enhanced the luminescence efficiency up to threefold compared with the core CdSe. MPA ligand shifted the initial hydrophobic quantum dots to hydrophilic ones, which helped to dissolve them in organic solvents and attach the antibody.

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Third-order nonlinear optical properties of CdSe/ZnS/CdSe core-shell-shell quantum dots

Physica E Low-dimensional Systems and Nanostructures ◽

10.1016/j.physe.2018.11.010 ◽

2019 ◽

Vol 107 ◽

pp. 24-29 ◽

Cited By ~ 4

Author(s):

Emusani Ramya ◽

M. Veeramohan Rao ◽

D. Narayana Rao

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Nonlinear Optical ◽

Nonlinear Optical Properties ◽

Core Shell ◽

Cdse Core ◽

Third Order

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Photochemical synthesis, investigation of optical properties and photocatalytic activity of CdTe/CdSe core/shell quantum dots

Materials Technology ◽

10.1080/10667857.2021.1988040 ◽

2021 ◽

pp. 1-7

Author(s):

Mehdi Molaei ◽

Farzad Farahmandzadeh ◽

Tahereh Sadat Mousavi ◽

Masoud Karimipour

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Photocatalytic Activity ◽

Photochemical Synthesis ◽

Core Shell ◽

Cdse Core

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Surface passivation assisted lasing emission in the quantum dots doped cholesteric liquid crystal resonating cavity with polymer template

RSC Advances ◽

10.1039/c4ra05787b ◽

2014 ◽

Vol 4 (95) ◽

pp. 52804-52807 ◽

Cited By ~ 7

Author(s):

Lin-Jer Chen ◽

Chia-Rong Lee ◽

Chung-Liang Chu

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Liquid Crystal ◽

Surface Passivation ◽

Cholesteric Liquid Crystal ◽

Core Shell ◽

Polymer Template

A copolymer has been used as a template for enhanced optical properties of core–shell CdS/ZnSe quantum dots doped cholesteric liquid crystal.

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Investigation of the Surface Passivation Effect on the Optical Properties of CsPbBr3 Perovskite Quantum Dots

Surfaces and Interfaces ◽

10.1016/j.surfin.2021.100948 ◽

2021 ◽

Vol 23 ◽

pp. 100948

Author(s):

Saif M.H. Qaid ◽

Hamid M. Ghaithan ◽

Bandar Ali Al-Asbahi ◽

Abdullah S. Aldwayyan

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Surface Passivation ◽

Perovskite Quantum Dots

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Influence of TOPO and TOPO-CdSe/ZnS Quantum Dots on Luminescence Photodynamics of InP/InAsP/InPHeterostructure Nanowires

Nanomaterials ◽

10.3390/nano11030640 ◽

2021 ◽

Vol 11 (3) ◽

pp. 640

Author(s):

Artem I. Khrebtov ◽

Vladimir V. Danilov ◽

Anastasia S. Kulagina ◽

Rodion R. Reznik ◽

Ivan D. Skurlov ◽

...

Keyword(s):

Quantum Dots ◽

Excited States ◽

Molecular Beam ◽

Surface Passivation ◽

Low Energy ◽

Trioctylphosphine Oxide ◽

Reverse Transfer ◽

Semiconductor Heterostructure ◽

Ligand Type

The passivation influence by ligands coverage with trioctylphosphine oxide (TOPO) and TOPO including colloidal CdSe/ZnS quantum dots (QDs) on optical properties of the semiconductor heterostructure, namely an array of InP nanowires (NWs) with InAsP nanoinsertion grown by Au-assisted molecular beam epitaxy on Si (111) substrates, was investigated. A significant dependence of the photoluminescence (PL) dynamics of the InAsP insertions on the ligand type was shown, which was associated with the changes in the excitation translation channels in the heterostructure. This change was caused by a different interaction of the ligand shells with the surface of InP NWs, which led to the formation of different interfacial low-energy states at the NW-ligand boundary, such as surface-localized antibonding orbitals and hybridized states that were energetically close to the radiating state and participate in the transfer of excitation. It was shown that the quenching of excited states associated with the capture of excitation to interfacial low-energy traps was compensated by the increasing role of the “reverse transfer” mechanism. As a result, the effectiveness of TOPO-CdSe/ZnS QDs as a novel surface passivation coating was demonstrated.

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Effect of dopant concentration and the role of ZnS shell on optical properties of Sm3+ doped CdS quantum dots

RSC Advances ◽

10.1039/d0ra08056j ◽

2021 ◽

Vol 11 (14) ◽

pp. 7961-7971

Author(s):

N. D. Vinh ◽

P. M. Tan ◽

P. V. Do ◽

S. Bharti ◽

V. X. Hoa ◽

...

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Dopant Concentration ◽

Core Shell ◽

Cds Quantum Dots ◽

Cds Qds

The role of samarium (Sm) dopant on the structural, morphological, and optical properties of CdS QDs and CdS/ZnS core/shell QDs was methodically reported.

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