scholarly journals Rapid Detection of Dimethoate in Soybean Samples by Microfluidic Paper Chips Based on Oil-Soluble CdSe Quantum Dots

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2810
Author(s):  
Xinpeng Yan ◽  
Zhong Zhang ◽  
Runguang Zhang ◽  
Tian Yang ◽  
Guoying Hao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Rapid Detection ◽  
Organophosphorus Pesticides ◽  
Gas Chromatography Mass Spectrometry ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Electron Transfer Mechanism ◽  
Soybean Sample ◽  
Functional Monomers ◽  
Paper Chip

Given the imperative of monitoring organophosphorus pesticides (OPs) residues in the ecosystem, here a novel, facile and sensitive fluorescence sensor is presented for the rapid detection of dimethoate. In this work, surface molecularly imprinted polymer (SMIP) and microfluidic technology had been introduced to enhance the selectivity and portability of the described methodology. Oil-soluble CdSe quantum dots (QDs) synthesized in a green way were used as fluorescent material for the selective detection of dimethoate on the basis of static quenching and photoinduced electron transfer mechanism. Among many kinds of paper materials, glass fiber paper was used as the novel substrate of paper chip due to low pristine fluorescence and better performance when combining CdSe QDs. In the process of molecular imprinting, the interaction between several functional monomers and dimethoate molecule was investigated and simulated theoretically by software to improve the selectivity of the sensor. Consequently, the fabricated novel detection platform could effectively respond to dimethoate in 10 min with the concentration range of 0.45–80 μmol/L and detection limit of 0.13 μmol/L. The recovery in the spiked experiment soybean sample was in an acceptable range (97.6–104.1%) and the accuracy was verified by gas chromatography-mass spectrometry, which signified the feasibility and potential in food sampling.

scholarly journals Intense Visible Luminescence in CdSe Quantum Dots by Efficiency Surface Passivation with H2O Molecules

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Hyeoung Woo Park ◽  
Do-Hyung Kim
Keyword(s):  
Heat Treatment ◽  
Quantum Dots ◽  
Quantum Yield ◽  
Surface Passivation ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Effect Of Water ◽  
Visible Luminescence ◽  
Luminescence Efficiency

We have investigated the effect of water (H2O) cooling and heat treatment on the luminescence efficiency of core CdSe quantum dots (QDs). The photoluminescence (PL) quantum yield of the CdSe QDs was enhanced up to ~85%, and some periodic bright points were observed in wide color ranges during the heat treatment of QDs mixed with H2O. The PL enhancement of QDs could be attributed to the recovery of QDs surface traps by unreacted ligands confined within the hydrophilic H2O molecule containers.

Developed one-pot synthesis of dual-color CdSe quantum dots for white light-emitting diode application

2018 ◽  
Vol 6 (12) ◽  
pp. 3089-3096 ◽  
Author(s):  
Sheng Dai ◽  
Cyuan-Bin Siao ◽  
Shu-Ru Chung ◽  
Kuan-Wen Wang ◽  
Xiaoqing Pan
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diode ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
One Pot ◽  
Synthetic Process ◽  
Light Emitting ◽  
One Pot Synthesis ◽  
Enhanced Stability

The size and fraction of red and green CdSe QDs can be controlled precisely during the synthetic process, thus manifesting remarkably enhanced stability.

Optimizing electron transfer from CdSe QDs to hydrogenase for photocatalytic H2 production

2019 ◽  
Vol 55 (39) ◽  
pp. 5579-5582 ◽  
Author(s):  
Monica L. K. Sanchez ◽  
Chang-Hao Wu ◽  
Michael W. W. Adams ◽  
R. Brian Dyer
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Reduction Potential ◽  
H2 Production ◽  
Cdse Quantum Dots ◽  
Redox Mediators ◽  
Cdse Qds ◽  
Electron Shuttles ◽  
Hydrogenase Enzyme

A series of viologen related redox mediators of varying reduction potential has been characterized and their utility as electron shuttles between CdSe quantum dots and hydrogenase enzyme has been demonstrated.

Switching-on superparamagnetism in diluted magnetic Fe(iii) doped CdSe quantum dots

CrystEngComm ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1738-1745 ◽  
Author(s):  
Amar Nath Yadav ◽  
Jasleen K. Bindra ◽  
Narendra Jakhar ◽  
Kedar Singh
Keyword(s):  
Quantum Dots ◽  
Exchange Interaction ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Ferromagnetic Exchange ◽  
Diluted Magnetic ◽  
Weak Ferromagnetic

Chemically prepared, 0.5% Fe(iii)-doped CdSe QDs exhibit superparamagnetism with weak ferromagnetic exchange interaction.

Dependence of Luminescence Efficiency of CdSe Quantum Dots on Chemical Environments

2008 ◽  
Vol 8 (11) ◽  
pp. 5615-5623 ◽  
Author(s):  
Rajan Jose ◽  
Mitsuru Ishikawa ◽  
Velmurugan Thavasi ◽  
Yoshinobu Baba ◽  
Seeram Ramakrishna
Keyword(s):  
Quantum Dots ◽  
Cadmium Acetate ◽  
Trioctylphosphine Oxide ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Luminescence Efficiency ◽  
Cadmium Stearate

Dependence of photoluminescence (PL) efficiency (ΦPL) of CdSe quantum dots (QDs) on coordinating solvents, precursors, and dispersing solvents was investigated. The ΦPL of CdSe QDs was ∼0.05 when synthesized at 120 °C using the precursors, cadmium acetate (CdAc) and trioctylphosphine selenide (TOPSe) in trioctylphosphine (TOP). The ΦPL was increased from 0.05 to ∼0.1 when coordinating solvents, trioctylphosphine oxide (TOPO) and hexadecylamine (HDA), were added to the above reaction mixture. The ΦPL was dramatically increased from ∼0.1 to ∼0.7 when CdAc was replaced by cadmium stearate (CdSt). The ΦPL of CdSe QDs synthesized using cadmium stearate (CdSt)/TOPSe/TOP/TOPO was measured in butanol, chloroform, hexane, and toluene and found that the ΦPL is strong dispersing solvent-dependent. The DFT analysis at b3lyp/lanl2dz level on the interaction of CdSe QDs with chemical environments showed that oxygen-containing molecules interact strongly with CdSe compared to non-oxygen containing molecules and could influence the ΦPL.

Optimized Synthesis of Water-Soluble and Small-Size CdSe Quantum Dots

2011 ◽  
Vol 266 ◽  
pp. 46-50
Author(s):  
Jiao Yun Xia ◽  
Jun Long Tang
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Water Soluble ◽  
Cdse Quantum Dots ◽  
Key Factors ◽  
Cdse Qds ◽  
High Quality ◽  
Synthesis Route ◽  
Initial Ph

An optimized synthesis route was applied for controlling the preparation of CdSe quantum dots (QDs) in an aqueous solution. Some key factors which influencing the properties of CdSe QDs, such as initial pH, ratio of precursor etc, were investigated. The as-prepared products have been characterized by TEM, XPS, XRD, UV-Vis and fluorescence (FL) spectra. The result showed that the high-quality CdSe QDs with 3 nm was obtained. The experiments also conformed that the CdSe QDs with better FL properties were obtained with properly initial pH, 5, suitably [Cd2+] / [SeSO3 2-], range from 1:0.25 to 1:0.75 and the ratio of [Cd2+] / [TGA] is 1:2~1:3.

High luminescent core–shell QDs based on noninjection synthesized CdSe QDs: observation of magic sized CdSe quantum dots

RSC Advances ◽  
2014 ◽  
Vol 4 (80) ◽  
pp. 42316-42325 ◽  
Author(s):  
Haifeng Zhou ◽  
Guangjun Zhou ◽  
Juan Zhou ◽  
Dong Xu ◽  
Xingshuang Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Core Shell ◽  
Cdse Quantum Dots ◽  
Cdse Qds

scholarly journals 3-Mercaptopropionic, 4-Mercaptobenzoic, and Oleic Acid-Capped CdSe Quantum Dots: Interparticle Distance, Anchoring Groups, and Surface Passivation

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
José Augusto Lucena dos Santos ◽  
Fabio Baum ◽  
Emerson Cristofer Kohlrausch ◽  
Fabiele C. Tavares ◽  
Tatiane Pretto ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Oleic Acid ◽  
Photocatalytic Oxidation ◽  
Surface Passivation ◽  
Interparticle Distance ◽  
Molecular Size ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Tem Analysis ◽  
C Nmr

The optoelectronic properties of quantum dots are strongly controlled by the chemical nature of their surface-passivating ligands. In this work, we present the synthesis, characterization, and surface modification of CdSe quantum dots (QDs) and their application in solar cells. CdSe QDs were capped in oleic acid (OA), 3-mercaptopropionic acid (MPA), and 4-mercaptobenzoic acid (MBA). The QDs were characterized by transmission electron microscopy (TEM), UV-Vis absorption and emission spectrophotometry, thermogravimetric analyses, and 1H and 13C NMR. From TEM analysis, it has been observed that interparticle distance can be effectively controlled by the presence of different molecular size ligands. From the 1H and 13C NMR, specific types of interactions between the Cd2+ and the ligands have been observed. Although CdSe/OA presented larger interparticle distance as compared to CdSe/MPA and CdSe/MBA, the photocatalytic oxidation of the thiol groups on the surface of the MPA- and MBA-based quantum dots resulted in poor surface stabilization, ultimately resulting in poor power conversion efficiencies which were ca. 70% smaller than that of OA-based solar cell.

scholarly journals CdSe Quantum Dots in Human Models Derived from ALS Patients: Characterization, Nuclear Penetration Studies and Multiplexing

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 671
Author(s):  
Carlota Tosat-Bitrián ◽  
Alicia Avis-Bodas ◽  
Gracia Porras ◽  
Daniel Borrego-Hernández ◽  
Alberto García-Redondo ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Mechanisms ◽  
Emission Spectra ◽  
Molecular Profiling ◽  
Proper Function ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Als Patients ◽  
Lateral Sclerosis ◽  
Narrow Emission

CdSe quantum dots (QDs) are valuable tools for deciphering molecular mechanisms in cells. Their conjugation with antibodies offers a unique staining source with optimal characteristics, including increased photostability and narrow emission spectra, allowing for improved multiplexing capabilities using a single excitation source. In combination with pathology models derived from patients, they have great potential to contribute to quantitative molecular profiling and promote personalized medicine. However, the commercial availability of diverse CdSe QDs is still limited and characterization techniques must be performed to these materials or the conjugates developed in the lab to assure a proper function and reproducibility. Furthermore, while there is significant data of QDs experiments in cell lines, the literature with primary human cells is scarce, and QD behavior in these systems may be different. Rigorous characterization data of commercially available QDs and their conjugates with biomolecules of interest is needed in order to establish their potential for target labelling and expand their use among research labs. Here we compare the characterization and labelling performance of different QD conjugates in SH-SY5Y cell line, fibroblasts and immortalized lymphocytes derived from amyotrophic lateral sclerosis patients.

HIGHLY ORDERED MICRO-ARRAYS OF CdSe QUANTUM DOTS ON CHEMICALLY PATTERNED SUBSTRATES

2009 ◽  
Vol 08 (01n02) ◽  
pp. 119-122
Author(s):  
LI ZHANG ◽  
HUA-YAN SI ◽  
HUA XU ◽  
HAO-LI ZHANG ◽  
YU-QING XIONG
Keyword(s):  
Quantum Dots ◽  
Cadmium Selenide ◽  
Self Assembly ◽  
Microcontact Printing ◽  
Cdse Quantum Dots ◽  
Two Dimensional ◽  
Liquid Interfaces ◽  
Patterned Substrates ◽  
Cdse Qds ◽  
Ordered Arrays

Highly ordered arrays consisting uniform fluorescent cadmium selenide ( CdSe ) quantum dots (QDs) ring or dot structures were obtained by self-assembly of QDs on chemically patterned substrates. In this method, Au substrates with alternating hydrophobic and hydrophilic square patterns are firstly fabricated by microcontact printing, which allows water droplets to condense on the hydrophilic regions to provide two-dimensional template arrays. The CdSe QDs are then assembled at the liquid/liquid interfaces to give uniform micro or nanostructures. The shape and size of the rings and dots can be tailored by controlling the relative evaporation speed of the water and the organic solvents. The obtained nanostructures have ideal topography to avoid substrate-induced fluorescence quenching.

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