JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2015
·
IF 3.368
Dongchen Che,Xiaoxu Zhu,Hongzhi Wang,Yourong Duan,Qinghong Zhang,Yaogang Li
Efficient synthetic methods for near-infrared quantum dots with good biophysical properties as bioimaging agents are urgently required. In this work, a simple and fast synthesis of highly luminescent , near-infrared AgInSe 2 –ZnSe quantum dots (QDs) with tunable emissions in aqueous media is reported. This method avoids high temperature and pressure and organic solvents to directly generate water-dispersible AgInSe 2 –ZnSe QDs. The photoluminescence emission peak of the AgInSe 2 –ZnSe QDs ranged from 625 to 940 nm, with quantum yields up to 31%. The AgInSe 2 –ZnSe QDs with high quantum yield, near-infrared and low cytotoxic could be used as good cell labels, showing great potential applications in bio-imaging.
研究领域:
材料科学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2013
·
IF 2.112
Qiu-Hang Chen,Jie Zhang,Guo-Ping Chen,Rui-Qian Guo
Spindle-liked ZnSe and Mn:ZnSe quantum dots (QDs) were formed via an optimized greener approach, which may be attributed to the amine ligands adhering asymmetrically to the crystal facets. Powder X-ray diffraction (XRD) patterns revealed that the ZnSe and Mn:ZnSe QDs have a zinc blende cubic crystal structure. The crystallite size of ZnSe was calculated to be about 4 nm from the (1 1 1) peak width using the Scherrer equation, which was in agreement with the HRTEM findings. The fluorescence emission peak of as-prepared ZnSe and Mn:ZnSe QDs was 431 nm and 580 nm respectively. We investigated the effect of the reaction temperature, reflux time, precursor solvent, size of MnSe core and overcoating temperature of ZnSe layer on the optical properties of ZnSe and Mn:ZnSe QDs. It is shown that the precursor solvent plays a key role in the formation of the magic-sized QDs (MSQDs). And as a result, doped quantum dots (d-dots) showed a large Stokes shift and enhanced photoluminescence, and smaller size of the MnSe core and suitable overcoating temperature of ZnSe shell were identified as two key parameters for obtaining the high quality d-dots.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Zhi-Qiang Zhou,Yuan-Ping Liao,Jing Yang,Shan Huang,Qi Xiao,Li-Yun Yang,Yi Liu
Developing simple and sensitive non-aggregation strategy for detecting Cd 2+ is necessary for improving the selectivity and sensitivity of probe. Here, we establish a simple, rapid and ratiometric strategy for the recognition of Cd 2+ based on the formation of core-shell ZnSe/CdS structure using ZnSe quantum dots (QDs). The transformation from binary ZnSe QDs to core-shell ZnSe/CdS QDs both change the elemental composition and structure of ZnSe QDs, leading to the changes in band gap of ZnSe QDs, which could be observed in the UV–vis spectra. In the detection process, ZnSe QDs only possess absorption peak at 343 nm, the formation of ZnSe/CdS after the addition of Cd 2+ leads to the appearance of the new peak at 397 nm, while other heavy metal ions could not cause the appearance of new absorption peak. Therefore, this strategy shows good selectivity for Cd 2+ detection. Based on this strategy, the limit of detection (LOD) for Cd 2+ is 11 nM by UV–vis spectroscopy with a desirable relation of linearity (R 2 = 0.999) between A 397 /A 343 and Cd 2+ contents, which is superior to the LOD of most reported nanomaterials . The response time for Cd 2+ detection is as short as 60 s, which is suitable for rapid detection. This ratiometric probe has also been applied to the detection of Cd 2+ in tap water samples, the recovery of Cd 2+ was between 94.9% and 105.6% for tap water samples, indicating the high accuracy of our ratiometric assay. Our strategy not only provided a new method for detecting Cd 2+ , but also put forward an implication that the band energy changes of QDs caused by heavy metal ions can be applied in the selective and sensitive detection of heavy metal ions.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Zhi-Qiang Zhou,Ren Yan,Jie Zhao,Li-Yun Yang,Ji-Lei Chen,Yan-Jun Hu,Feng-Lei Jiang,Yi Liu
The pollution of Hg 2+ is one of the most serious problems to human health due to their high toxicity, mobility, difficulty in degradation and ability of accumulation in ecological systems. Thus, it is of great importance to develop highly selective and sensitive probe for detecting Hg 2+ in aquatic ecosystems. Here we propose a new turn-on strategy for specific recognition and detection of Hg 2+ . Mn-doped ZnSe quantum dots (QDs) with small size (2.1 nm) were prepared and adopted as probe, the small size of doped QDs makes the replacement of Mn 2+ by Hg 2+ accessible, which eliminates the fluorescence quenching effect of superficial Mn 2+ on Mn-doped ZnSe QDs. Different from traditional semiconductor nanocrystals based turn-off probe for detecting Hg 2+ , we realize a turn-on strategy for the selective detection of Hg 2+ by Hg 2+ -Mn 2+ replacement using semiconductor nanocrystals (Mn-doped ZnSe QDs). This turn-on mechanism was verified by fluorescence spectra, ICP-AES and XPS. In the absence of Hg 2+ , Mn-doped ZnSe QDs possessed low fluorescence intensity. With the addition of Hg 2+ , the fluorescence intensity around 600 nm increased dramatically. Our Mn-doped ZnSe QDs exhibits excellent selectivity and sensitivity for Hg 2+ . The limit of detection is 7.0 nM, which is lower than the mercury toxic level defined by the U.S. Environmental Protection Agency (10 nM). The result of Hg 2+ detection in real samples indicates the feasibility and sensitivity of our probe for application in environmental samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Methods and Applications in Fluorescence
·
2017
·Vol. 5
·期 4
·045001
·
IF 2.656
Zhongchen Bai,Licai Hao,Zhaoling Huang,Shuijie Qin,Zhengping Zhang
We studied an enhancement effect of defect fluorescence of ZnSe quantum dots (QDs) on a heterojunction of ZnSe QDs and gold nanoparticles. The photoluminescence (PL) of Au/ZnSe heterojunction is excited by using a 150 nm diameter ultraviolet laser spot of a scanning near-field optical microscope. Owing to the charge transfer of photon-generated carriers from ZnSe QDs, the enhanced PL effect is observed, which results from the increase of the built-in electric field to hinder the electron transfer to gold nanoparticles and is trapped by the defect states of ZnSe QDs. The broadening of defect fluorescence spectra and the reduction of excitonic fluorescence in multi-heterojunction of ZnSe QDs and gold nanoparticles are also observed which is attributed to an increase of their contact areas. We believe that enhanced defect fluorescence method described in this paper have potential applications in forming uniform optoelectronic heterojunction in controlling and boosting fluorescent efficiency of weak PL devices.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
Nano Research
·
2024
·
IF 9.5
He Jinhua,Wang Chenhui,Liu Mingrui,Ramzan Muhammad,Long Zhiwei,Wu Xian-gang,Chen Yu,Zhong Haizheng
The potential use of large-size ZnSe quantum dots as blue emitters for display applications has greatly inspired the colloidal synthesis. Herein, we report the negative effects of side reactions of large-size ZnSe quantum dots. The side reactions between oleic acid and oleylamine generated amidation products and H 2 O, which led to the hydrolysis of Zn(OA) 2 to Zn(OH) 2 and the subsequent formation of zinc oxide (ZnO) and zinc bis[diphenylphosphinate] (Zn(DPPA) 2 ) precipitates. These side reactions resulted in the formation of a defective surface including a Se-rich surface and oxygen-related defects. Such negative effects can be overcome by adopting an etching strategy using potassium fluoride and myristic acid in combination. By overcoating a ZnS shell, blue emissive ZnSe/ZnS quantum dots with a maximum photoluminescence quantum yield of up to 91% were obtained. We further fabricated ZnSe quantum dots-based blue light-emitting diodes with an emission peak at 456 nm. The device showed a turn-on voltage of 2.7 V with a maximum external quantum efficiency of 4.2% and a maximum luminance of 1223 cd·m −2 .
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2010
·
IF 4.224
Lai-Jun Zhang,Xing-Can Shen,Hong Liang,Jia-Ting Yao
Four families of magic-sized ZnSe quantum dots (ZnSe MSQDs) with the first exciton absorption peaks at 280 nm (F280), 291 nm (F291), about 319 nm (F319), and 347 nm (F347) were synthesized using fatty amine−H2Se complex as selenium precursor via noninjection one-pot or hot-injection approaches. The formation, growth, and transformation of these families of ZnSe MSQDs were monitored mainly by ultraviolet−visible absorption spectroscopy. Relatively pure F291 and F347 were obtained via the combination of hot-injection technology with purification treatment and were further characterized using mass spectroscopy, infrared spectroscopy, fluorescence spectroscopy, transmission electron microscopy, and X-ray powder diffraction. F291 and F347 are speculated to be [(Zn7Se7)(OLA)2(OA)] (OLA = oleylamine, OA = octylamine) and [(Zn16Se15)(OLA)7], respectively, by analyzing the corresponding mass and the infrared and absorption spectra; both emit narrow exciton fluorescence with relatively small stokes shift of 9 and 2 nm, respectively. Ultrafine ZnSe nanorods with a diameter of about 1.7 nm formed via oriented attachment of F347 were observed using transmission electron microscopy. Fatty amine−H2Se complex has been demonstrated to be a simple, phosphine-free, low-cost, and effective selenium precursor for the synthesis of ZnSe MSQDs or regular quantum dots (RQDs).
研究领域:
材料科学
·
纳米技术
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 36
·5274-5280
·
IF 1.9
Yurong Tang,Shuguang Yan,Hang Ye,Fenglan Zheng,Liu Feng,Feng Liu,Xulong Li
The design of quantum dots as a new sensing platform is very important for developing high-sensitivity fluorescent sensors. However, achieving a new strategy is still a great challenge. Here, a new strategy for fabricating water-dispersible thiol malic acid modified ZnSe quantum dots (TMA-ZnSe QDs) is presented in aqueous solution. The characteristics of the modified TMA-ZnSe QDs and the interactions between TMA-ZnSe QDs, Al3+ and rutin were investigated by atomic force microscopy, energy dispersive X-ray spectroscopy, fluorescence spectrometry, resonance Rayleigh scattering, UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy. A new high-sensitivity fluorescent sensor based on tuning the aggregation/disaggregation behavior of TMA-ZnSe QDs by structure-switching for the detection of rutin was developed. The results confirmed that the detection sensitivity was greatly improved by the aggregation of TMA-ZnSe QDs with Al3+ because rutin effectively quenched the FL of TMA-ZnSe QDs–Al3+via the photoinduced electron transfer process. Under optimum conditions, the decrease in the FL intensity was linear to the rutin concentration from 0.02 μg mL−1 to 9 μg mL−1 and the detection limit for rutin was 0.02 μg mL−1. The proposed method offered a new possibility for rutin detection in real samples owing to its low cost, simplicity, high sensitivity and good stability. The present work provides a new strategy for improving sensitivity by tuning the aggregation/disaggregation behavior of TMA-ZnSe QDs.
研究领域:
分析化学
·
纳米生物技术
·
分子诊断
·
药物分析
·
荧光传感
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Dong Li,Xiaoxiao He,Litao Zhao,Haoyang Li,Yu Zhao,Sanjun Zhang,Xiaolei Zhang,Jinquan Chen,Qingyuan Jin,Jianhua Xu
In this article, by connecting positively charged cysteamine-coated ZnSe quantum dots (QDs) with either negatively charged graphene oxide (GO) or reduced graphene oxide (RGO), we have assembled ZnSe-GO and ZnSe-RGO composite materials, respectively. We used time-correlated single photon counting (TCSPC) and femtosecond transient absorption (TA) to study the effects of GO/RGO on the fluorescence and carrier transport dynamics of ZnSe QDs. We confirmed that the strong excited state interaction between GO/RGO and ZnSe QDs could significantly quench the exciton fluorescence of ZnSe QDs. Picosecond ultrafast electron transfer from ZnSe QDs to GO/RGO surfaces has been found, and it can decrease the bleaching signal intensity of ZnSe QDs and accelerate the recovery of the bleaching signal as well. Moreover, we found that the energy level change caused by the GO reduction reduced the energy level difference between RGO and ZnSe QDs, which implies broader application prospects for ZnSe-RGO vs. ZnSe-GO composite.
研究领域:
材料科学
·
光物理学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Junrui Zhou,Bowei Li,Anjin Qi,Yajun Shi,Ji Qi,Huizhong Xu,Lingxin Chen
In this study, a newly fluorescent ZnSe quantum dots (QDs) with ion imprinting technology was firstly realized on the three-dimensional (3D) rotary paper–based microfluidic chip platform which can be used to realize specific and multiplexed detection of Cadmium ions (Cd 2+ ) and Lead ions (Pb 2+ ). Compared to CdTe quantum dots, ZnSe quantum dots are less toxic and more environmental friendly. In addition, this design improved the portability of the device by transferred the liquid phase of ZnSe QDs@ion imprinted polymers to solid glass fiber paper. Moreover, the 3D rotary microfluidic chip ( μ PADs) showed great advantages including low cost, simple and fast facile operation, multiplexed detection, and showed good sensitivity and selectivity. Under optimal experiment conditions, our proposed method was enabled to realize specific and multi-channel determination of Cd 2+ and Pb 2+ ions. The developed sensor of Cd 2+ μ PADs provided a linear response from 1 to 70 μg/L with a lower detection limit of 0.245 μg/L, and Pb 2+ μ PADs provided a linear response from 1 to 60 μg/L with a lower detection limit of 0.335 μg/L, respectively. Excitingly, this newly designed 3D rotary μ PADs exhibited quantitative information conveniently, which showed the promising application prospects to rapid testing target metal ions in environmental in the future.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2018
·Vol. 124
·期 7
·1-6
·
IF 1.604
Peng Man,Bai Zhongchen,Li Xianji,Zhang Ying,Zhang Zhengping
We present a wide-spectrum photoluminescence (PL) enhancement effect on the multi-heterojunction of ZnSe quantum dots and gold nanoparticles (NPs). The Au/ZnSe heterojunction is fabricated using Langmuir–Blodgett assembling method. The photoluminescence is measured using a 150 nm aperture ultraviolet laser beam spot of a scanning near-field optical microscope. The enhancement of band-gap emission and defect PL, the quenching of the fluorescence are, respectively, observed, which depend on the distance of gold NPs and ZnSe quantum dots. The enhancement of the band-gap emission is ascribed to the local field enhancement induced by the resonant coupling between the excitons of ZnSe and the surface plasmons of gold NPs. The enhancement of the defect PL is a result of the electron trapped by the defect states in the process of transporting electrons from ZnSe QDs to gold NPs due to the increase of the built-in electric field to hinder the electron transfer to gold nanoparticles. In addition, the quenching of the fluorescence is due to the electron transfer from ZnSe quantum dots to gold NPs. Our result opens the possibility of applications in forming uniform optoelectronic heterojunction and in controlling fluorescent efficiency of PL devices.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 8
·2824-2835
·
IF 7.367
Zhi-Qiang Zhou,Li-Yun Yang,Ren Yan,Jie Zhao,Yu-Qi Liu,Lu Lai,Feng-Lei Jiang,Thomas Maskow,Yi Liu
Although cation exchange (CE) has been studied for many years and some mechanisms were proposed, there is still a knowledge gap in CE and problems such as the need for high temperature and it being time-consuming are still unaddressed. We developed a new mild strategy for CE by introducing a new ideal template and first applied this doping strategy to detect Cd2+ and Hg2+. This strategy adopted Mn-doped ZnSe quantum dots (QDs) as the template and the introduction occurs via a two-step CE reaction: first Zn2+ was partially substituted by X (X = Cd2+, Hg2+, Cu2+, Ag+ or Pb2+), later Mn2+ (in the deep structure of QDs) was substituted by X. Remarkably, Mn2+ in the lattice can be easily substituted by a dopant and its replacement by a dopant helps to bury the metal ions. The ultra-fast introduction of Cd2+ and Hg2+ (70 minutes for Cd2+ and 19 minutes for Hg2+) was realized at room temperature; other metal ions such as Ag+, Cu2+ and Pb2+ can be buried at 50 °C. This mild reaction temperature offers a solution for introducing impurities without sacrificing the interfacial structure of nanocrystals. HRTEM, XPS and ICP measurements were applied to analyze the introduction process. Furthermore, the spectroscopic method was employed to analyze the introduction, migration and distribution of metal ions. Then, we proposed a mechanism for the chemical conversion of nanocrystals by CE. Through this strategy, full-color light-emitting doped QDs were fabricated. Strikingly, a new turn-on probe for the detection of Cd2+ and Hg2+ with improved selectivity was developed by adopting this doping strategy. The detection limit is 36 nM for Cd2+ and 20 nM for Hg2+, which is competitive with the limit of detection reported by other groups using QDs as sensors.
研究领域:
材料科学
·
化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）