CHEMICAL PHYSICS LETTERS
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2017
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IF 1.815
Shuning Liu,Chenchen Liu,Xinying Luan,Rui Yao,Yakai Feng
The far-red/near infrared photoluminescence of zinc phthalocyanines would be strongly quenched once they are aggregated, which will obviously hinder their wide applications in environmental, energy related and biomedical fields. Herein, the ultra-small sized semiconductor quantum dots with core-shell structures (CdSe@CdS) have been firstly synthesized and then assembled with a dendritic zinc phthalocyanine (ZnPc) in the H 2 O/DMF mixed solvent to obtain monodispersed nanospheres. Finally, it was found that the resultant ethanolic colloids can be employed as a sensitive and specific fluorescent nanoprobe for silver ions discrimination with a limit of detection (LOD) approaching to 10 − 8 mol/L.
研究领域:
材料科学
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分析化学
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环境科学
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高影响因子
CHEMOSPHERE
·
2017
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IF 4.208
Xu Chen,Yong Sik Ok,Dinesh Mohan,Charles U. Pittman,Xiaomin Dou
The increasingly wide use of semiconductor nanocrystals inevitably leads to their release into aquatic environment. The aggregation behaviors of 3-mercaptopropionic acid-capped CdSe/CdS core-shell quantum dots (MPA-QDs) under various water chemistry conditions were examined and their removal using Fe 3+ and Al 3+ coagulants was evaluated. Cationic species rather than concentrations affected the stability of MPA-QDs. Adding 2 mM Ca 2+ led to a much larger ζ-potential decrease and particle size increase than adding 150 mM K + at each tested solution pH. This indicated that complexation and depletion of surface-bound carboxyl groups by divalent Ca 2+ has a more pronounced effect than compression of the electrical double layer by high concentrations of monovalent K + . The presence of humic acid increased the stability of MPA-QDs, which might increase negative surface charging via overcoating or bind to the surface of MPA-QDs. The nanoparticles exhibited similar aggregation kinetics patterns in tap water and seawater, but varying patterns in the lake water because of the co-existence of 2.3 mM total of Ca 2+ and Mg 2+ . MPA-QDs (5 mg L −1 ) were readily coagulated by 2.4 mM Al 3+ or 1.2 mM Fe 3+ in tap water. Al 3+ and Fe 3+ can bind with carboxyl groups of the surface capping ligands, neutralize the negative charges on the surface of MPA-QDs and decrease the electrostatic repulsion forces to induce MPA-QDs aggregation. In addition, MPA-QDs could be bound with and wrapped into the flocs of hydrolysis products of coagulants. The results reported here could help broaden our understanding of the impacts and remediation of water-dispersed core-shell QD nanoparticles.
研究领域:
环境科学
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纳米生物学
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DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 10
·9363-9371
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IF 2.195
Xue Xiangxin,Chen Lei,Zhao Cuimei,Wang Hairui,Nie Ping,Chang Limin
In this paper, the photocatalytic behavior of CdSe/CdS quantum dots (QDs) in reducing the graphene oxide (GO) with different surface ligands was investigated. Here, three surface ligands of different functional groups (oleic acid, poly (acrylic acid polymers) and S 2− ) were selected to study the influence of surface ligands on photocatalytic behavior of the CdSe/CdS QDs. Meanwhile, the obtained samples can be used as photocatalyst, and the photocatalytic activity was evaluated by photodegrading a methylene blue solution. It turned out that the QDs–S 2− –GO sample showed the highest photocatalytic activity under visible-light irradiation. Different surface ligand has different influence on the charge separation efficiency, which has different influence on photocatalytic behavior. The results show that the photocatalytic behavior is highly dependent on the electron attracting ability of the surface ligands on the CdSe/CdS QDs. Finally, a possible photocatalytic mechanism is proposed.
研究领域:
材料科学
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光催化
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DOI
高影响因子
JOURNAL OF POLYMER ENGINEERING
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2022
·Vol. 42
·期 8
·787-793
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IF 1.624
Zhiyi Zhang,Zhichun Li,Fengbo Zhu,Lan Jia,Yudong Wang,Jingxin Zhu,Yanlong Ma,Hongwei He,Yuyuan Fan,Ying Zhang,Pengfei Fei,Yu Feng
Polyacrylonitrile (PAN) was often used as a composite fiber matrix due to its good spinning characteristics. Herein, photoluminescent quantum dot-doped nanofibers with tunable diameters were successfully prepared using electrospinning by adding CdSe/CdS quantum dots (QDs) in PAN spinning solution. The morphology and structure of CdSe/CdS-PAN nanofibers were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR), and the mechanical and photoluminescent properties of CdSe/CdS-PAN nanofibers were investigated. Stable photoluminescent nanofibers were obtained owning to the improved stability of photoluminescent property of CdSe/CdS QDs in the PAN nanofiber. The stable photoluminescent CdSe/CdS-PAN nanofibers might be used for anti-fake labels, ultraviolet sensors, smart textiles and optoelectronic devices.
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
ACS Applied Bio Materials
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2018
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IF 0
Xiaohong He,Xue Shen,Dongming Li,Yiyao Liu,Kun Jia,Xiaobo Liu
Nanoparticles exhibiting good biocompatibility and multifunctional optical, magnetic, and reactive properties are essential materials for the construction of next generation theranostics platforms. The core–shell structured CdSe@CdS is one of few semiconductor quantum dots (QD) that shows ideal photoluminescence for biological application including unity quantum yields, identical photoluminescence for ensembles and single dot, nonblinking, and antibleaching. However, overcoming toxicity concerns from Cd2+ is still a great challenge for promoting the practical medical application of the CdSe@CdS QD. Besides, the high quality luminescent and superparamagnetic nanoparticles at present are basically hydrophobic, which implies that the phase transfer of these functional nanoparticles into aqueous phase is the primary step to enable their biomedical application. Herein, we have developed a facile protocol to fabricate highly biocompatible nanoparticles showing both modulated luminescent and magnetic properties via a one-step self-assembling of amphiphilic block copolyarylene ether nitriles (amPEN), oleic acid stabilized CdSe@CdS QD, and Fe3O4 superparamagnetic nanoparticles (SP) in microemulsion system. Benefiting from the aromatic backbone structure of amPEN and its strong hydrophobic interaction with surface capping agent of QD/SP, the fabricated hybrid nanoprobe exhibits quite competitive colloids stability as well as fluorescent/magnetic properties, which ensures its application for in vitro fluorescence and magnetic resonance (MR) imaging of cancer cells.
研究领域:
生物医学工程
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材料科学
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纳米医学
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DOI
PubMed
Analytical Methods
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2019
·Vol. 12
·期 4
·491-498
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IF 2.378
Zhang-Jin He,Tian-Fang Kang,Li-Ping Lu,Shui-Yuan Cheng
In this study, a novel electrochemiluminescence (ECL) biosensor based on a CdSe@CdS quantum dot (QD)-functionalized MoS2-modified electrode was developed for the sensitive detection of mercury ions. Polycationic poly(diallyldimethylammonium chloride) (PDDA) and negatively charged QDs were adsorbed on the surface of MoS2, in sequence, to form the QD–PDDA–MoS2 composites, which were employed as matrices for immobilizing thymine-rich DNA sequences (DNA1). The gold nanoparticles (AuNPs) were combined with another type of thymine-rich DNA sequences (DNA2) and glucose oxidase (GOD) to prepare the GOD–AuNP–DNA2 conjugates. The composites were characterized via UV-visible absorption spectroscopy, fluorescence and transmission electron microscopy. A thymine–Hg2+–thymine complex was formed through Hg2+ mismatching with DNA1 and DNA2. GOD was, therefore, modified onto the electrode surface. GOD catalyzed the reduction of dissolved oxygen by glucose to produce hydrogen peroxide, which was a co-reactant of the QDs. The electrochemiluminescence signal of the biosensor increased linearly with the increase in the Hg2+ concentration over the range from 1.0 × 10−12 to 1.0 × 10−6 M with a detection limit of 1 × 10−13 M. The reproducibility, stability and specificity of the biosensor was also studied. The biosensor was used to determine Hg2+ in a real water sample and satisfactory results were obtained.
研究领域:
分析化学
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环境科学
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生物传感技术
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高影响因子
Nanoscale
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2021
·Vol. 13
·期 46
·19474-19483
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IF 7.79
Weishuo Xing,Shuang Zhang,Ruoting An,Wengang Bi,Chong Geng,Shu Xu
Tetrapod CdSe/CdS quantum dots (QDs) have attracted extensive research interest in light-emitting applications due to their anisotropic optical properties and large absorption cross-section. Traditional synthesis methods for tetrapod CdSe/CdS QDs usually employ fatty phosphonic acid ligands to induce the growth of wurtzite CdS arms on cubic CdSe QDs at high temperatures (350–380 °C). Here, a low temperature (120 °C) route was developed for the synthesis of tetrapod CdSe/CdS QDs using mixed amine ligands instead of phosphonic acid ligands. A study of the growth mechanism reveals that the amine ligands induce the orientation growth of cubic CdS arms on wurtzite CdSe QDs through a pyramid-shaped intermediate structure. The low reaction temperature facilitates the growth control of the tetrapod CdSe/CdS QDs through a microfluidic reactor. This study substantially simplifies the synthetic chemistry for the anisotropic growth of CdS on CdSe QDs, paving the way for green and economic production of tetrapod CdSe/CdS QDs towards efficient light-emitting applications.
研究领域:
材料科学
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纳米技术
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化学工程
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DOI
PubMed
高影响因子
Analytical Methods
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2017
·Vol. 10
·期 1
·51-58
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IF 1.9
Xiao-Li Du,Tian-Fang Kang,Li-Ping Lu,Shui-Yuan Cheng
A novel electrochemiluminescence (ECL) biosensor based on CdSe@CdS quantum dots (QDs) functionalized MoS2 modified electrode was developed for sensitive detection of Pb(II) using HRP-mimicking DNAzyme biocatalytic precipitation (BCP) for ECL signal quenching. Polycationic poly(diallyldimethylammonium chloride) (PDDA) and negatively charged QDs were adsorbed on the surface of MoS2, in sequence, to form the MoS2–QDs composites, which were employed as a matrix for the immobilization of the G-rich DNA strand, i.e., T30695. The MoS2–QDs were characterized by UV-vis absorption spectroscopy, fluorescence spectroscopy, energy dispersive spectrometry, transmission electron microscopy, and field emission scanning electron microscopy. CdSe@CdS QDs can produce an ECL signal using 0.1 M K2S2O8 as a co-reactant. T30695 can combine with Pb(II) ions to form a stable parallel G-quadruplex. The G-quadruplex can further combine with hemin to form DNAzyme, which can catalyze H2O2 and oxidize 4-chloro-1-naphthol (4-CN) to produce an insoluble precipitation of benzo-4-chlorohexadienone on the surface of the sensor. When the concentration of Pb(II) in the solution was increased, more of DNAzyme was generated and subsequently more 4-CN molecules were oxidized catalytically, leading to a decrease of the ECL signal. Using this quenching strategy, the ECL signal of the biosensor was linearly dependent on the logarithm of the Pb(II) concentration ranging from 1.0 × 10−15 to 1.0 × 10−11 M with a detection limit of 0.98 f M. The stability and selectivity of the sensor were also investigated. The sensor was applied in the determination of Pb(II) in the real water samples and satisfactory results were obtained.
研究领域:
分析化学
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环境科学
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纳米技术
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生物传感器
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DOI
高影响因子
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