Micromachines
·
2023
·Vol. 14
·期 5
·902
·
IF 3.4
Yong Xie,Chao Bian,Mingjie Han,Ri Wang,Yang Li,Yuhao Xu,Shanhong Xia
A highly sensitive and accurate dual-signal strategy is developed for trace Cu2+detection based on the inner filter effect (IFE) between Tween 20-gold nanoparticles (AuNPs) and CdSe/ZnS quantum dots (QDs). Tween 20-AuNPs are utilized as colorimetric probes and excellent fluorescent absorbers. The fluorescence of CdSe/ZnS QDs can be quenched efficiently by Tween 20-AuNPs via IFE. In the presence of D-penicillamine, D-penicillamine induces the aggregation of Tween 20-AuNPs and the fluorescent recovery of CdSe/ZnS QDs at high ionic strength. Upon addition of Cu2+, D-penicillamine tends to selectively chelate with Cu2+and then forms the mixed-valence complexes, which consequently inhibits the aggregation of Tween 20-AuNPs and the fluorescent recovery. The dual-signal method is used to quantitatively detect trace Cu2+, with low detection limits of 0.57 μg/L and 0.36 μg/L for colorimetry and fluorescence, respectively. In addition, the proposed method using a portable spectrometer is applied to the detection of Cu2+in water. This sensitive, accurate and miniature sensing system has potential in environmental evaluations.Keywords:fluorescence;colorimetry;copper;CdSe/ZnS quantum dots;gold nanoparticles;inner filter effect
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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产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2021
·Vol. 13
·期 20
·2305-2312
·
IF 2.896
Quanxiu Zhou,Zhaofa Li,Qunfang Wang,Liang Peng,Shihe Luo,Feng Long Gu
In this work, poly(styrene-co-maleic anhydride)-capped CdSe/ZnS quantum dots (QDs) aminolyzed with ethanolamine are proposed as fluorescent probes for the detection of Cu2+ and Hg2+, and two different quenching mechanisms are discussed in detail. The coordination abilities of the surface polymer of CdSe/ZnS QDs and two metal ions are calculated by density functional theory (DFT). The photoinduced electron transfer from excited QDs to Cu2+ unoccupied orbitals is enhanced due to the coordination between Cu2+ and the surface polymer of QDs. The electron transfer consumes non-radiative energy and performs fluorescence quenching. For Hg2+, the formation of HgS and the slight aggregation of polymer-coated CdSe/ZnS QDs lead to fluorescence quenching. The probe is sensitive to both Cu2+ and Hg2+, and the response can be detected within 1 min without adjusting the pH. With the addition of a masking agent, Cu2+ and Hg2+ can be exclusively detected in coexistence with another ion. For Cu2+, a linear relation in the concentration ranging from 0.02 to 0.7 μM was found between the relative fluorescence intensity (F0/F) and the concentration of Cu2+; the limit of detection (S/N = 3) is 6.94 nM. For Hg2+, a linear relation ranging from 0.1 to 1.4 μM was found between ln(F0/F) and the concentration of Hg2+; the limit of detection is 20.58 nM.
研究领域:
分析化学
·
材料科学
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Haiyu Li,Wan Wang,Zhijuan Wang,Qing Lv,Hua Bai,Qing Zhang
CdSe/ZnS quantum dots (QDs) and 3,3,5,5-tetramethylbenzidine (TMB) were incorporated into a filter paper to produce a paper-based colorimetric device for Hg 2+ detection. Under visible light, the CdSe/ZnS QDs acted as a photocatalyst to oxidize TMB, resulting in blue colorization on the paper. Moreover, Hg 2+ could enhance the photocatalytic activity of CdSe/ZnS QDs and consequently caused an increase in the color intensity of the paper. The color change of the paper-based device can be directly identified by naked-eye observation or captured by a smartphone and analyzed using image processing software for quantitative analysis. Under optimal conditions, a low detection limit of 0.09 µM was achieved. This device was applied for real samples, including tap water and cosmetics, and achieved satisfying results.
研究领域:
分析化学
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环境科学
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产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-13
·
IF 2.481
Li Chao,Ji Yang,Wang Can,Liang Shujing,Pan Fei,Zhang Chunlei,Chen Feng,Fu Hualin,Wang Kan,Cui Daxiang
Successful development of safe and highly effective nanoprobes for targeted imaging of in vivo early gastric cancer is a great challenge. Herein, we choose the CdSe/ZnS (core-shell) quantum dots (QDs) as prototypical materials, synthesized one kind of a new amphiphilic polymer including dentate-like alkyl chains and multiple carboxyl groups, and then used the prepared amphiphilic polymer to modify QDs. The resultant amphiphilic polymer engineered QDs (PQDs) were conjugated with BRCAA1 and Her2 monoclonal antibody, and prepared BRCAA1 antibody- and Her2 antibody-conjugated QDs were used for in vitro MGC803 cell labeling and in vivo targeted imaging of gastric cancer cells. Results showed that the PQDs exhibited good water solubility, strong photoluminescence (PL) intensity, and good biocompatibility. BRCAA1 antibody- and Her2 antibody-conjugated QD nanoprobes successfully realized targeted imaging of in vivo gastric cancer MGC803 cells. In conclusion, BRCAA1 antibody- and Her2 antibody-conjugated PQDs have great potential in applications such as single cell labeling and in vivo tracking, and targeted imaging and therapeutic effects' evaluation of in vivo early gastric cancer cells in the near future.
研究领域:
生物医学工程
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纳米医学
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肿瘤学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 1
·1-10
·
IF 5.479
Wen Shao-Hua,Liang Ru-Ping,Zeng Hui-Hui,Zhang Li,Qiu Jian-Ding
A ratiometric fluorometric method is described for the determination of arsenate via its inhibitory effect on the activity of the enzyme acid phosphatase. A nanoprobe was designed that consists of CdSe/ZnS quantum dots (QDs) coated with the terbium(III) complex of guanosine monophosphate (Tb-GMP). The nanoprobe was synthesized from carboxylated QDs, Tb(III) and GMP via binding of Tb(III) by both the carboxy and the phosphate groups. The nanoprobe, under single-wavelength excitation (at 280 nm), displays dual (red and green) emission, with peaks at around 652 nm from the QDs, and at 547 nm from the Tb-GMP coordination polymers. It is shown to be a viable nanoprobe for fluorometric determination of As(V) detection through it inhibitory action on the activity of acid phosphatase (ACP). The enzyme destroys the Tb-GMP structure via hydrolysis of GMP, and hence the fluorescence of the Tb-GMP complex is quenched. In contrast, the fluorescence of the CdSe/ZnS QDs remains inert to ACP. It therefore can serve as an internal reference signal. In the presence of arsenate (an analog of phosphate), the activity of ACP is inhibited due to competitive binding. Thus, hydrolysis of GMP is prevented. These findings were used to design a ratiometric fluorometric method for the quantification of As(V). The ratio of fluorescences at 547 and 652 nm increases linearly in the 0.5 to 200 ppb As(V) concentation range, and the limit of detection is 0.39 ppb. Under a UV lamp, the probe shows distinguishable color from green to red on increasing the concentration of As(V).
Schematic illustration of CdSe/ZnS quantum dot coated with carboxy-PEG and modified with the terbium(III)-GMP complex as a fluorescent nanoprobe for ratiometric determination of arsenate via its inhibition of ACP activity.
研究领域:
生物化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES
·
2023
·
IF 2
Yajie Liu,Yao Zhu,Xinyu Liu,Liming Dong,Qinglin Zheng,Shu Kang,Yahui He,Jing Wang,A. M. Abd El-Aty
The copper ion was detected rapidly by a novel sensing membrane in this paper for its damage to health and the environment. CdSe/ZnS QDs modified polyethersulfone membrane (QDs@PESM) was made by phase-inversion method using a membrane separation technique and quantum dots (QDs). When the sample passed through the membrane, the copper ions in the sample caused the membrane’s fluorescence to be quenched. The fluorescence quenching value of the membrane is used to calculate the concentration of copper ions. With R2= 0.9964, Cu2+could be quantitatively detected over a wide concentration range (10–1000 μg/L). The method’s LOD and LOQ were 4.27 and 14.23 μg/L, respectively. When the CdSe/ZnS QDs@PESM was used to analyze Cu2+ in various real drinks, including well water, baijiu, orange juice, beer, and milk, the recovery ranged from 79.1 to 123.9%, indicating that the CdSe/ZnS QDs@PESM can be used as a rapid, simple and reliable method to determine Cu2+ in various matrices.
研究领域:
环境科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2019
·
IF 4.309
Ali Shmshad,Jialun Tang,Imran Muhammad,Dengbao Han,Xin Zhang,Shuai Chang,Qingfan Shi,Haizheng Zhong
Colloidal quantum dots (QDs) are talented materials and have been extensively investigated in the field of photonics and optoelectronics due to their size-dependent optical properties. The core/shell structure of QDs with a wide band gap shell has been adopted for obtaining stable emission and high photoluminescent (PL) quantum efficiency. However, when employed in active devices such as light-emitting diodes (LEDs), the thick-shell structure of QDs may impede the transportation of carriers, thus deteriorating the device performance. In this work, the effect of the shell thickness of CdSe/ZnS QDs on the device performance is systematically studied through impedance spectroscopy, by constructing the electron-only symmetric device architecture. It is found that the evolution of capacitance in the symmetric device under applied voltage reflects the charge accumulation within the device and predicts the LED performance. The lowest capacitance is evaluated in the symmetric device containing QDs with a medium shell size of 2.1 nm, showing improved performance in the LED with the highest luminance and current efficiency of 26 370 cd/m2 and 8.3 cd/A, respectively.
研究领域:
光子学
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光电学
·
材料科学
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DOI
高影响因子
Frontiers in Chemistry
·
2019
·
IF 3.782
Hong Sihui,She Yongxin,Cao Xiaolin,Wang Miao,He Yahui,Zheng Lufei,Wang Shanshan,Abd El-Aty A. M.,Hacimüftüoglu Ahmet,Yan Mengmeng,Wang Jing
In the present study we have developed a direct competitive CdSe/ZnS quantum dot (QD) fluorescence assay based on micro-array-imprinted membranes for the determination of triazophos in cabbage and apple. The imprinted membranes were directly synthesized on the surface of a 96-well plate by thermal polymerization using triadimefon as the dummy template. Under optimal conditions, the assay showed an excellent linear response over the concentration ranges of 0.1–10,000 μg L−1 with a good coefficient of determination (R2= 0.982). The sensitivity (IC50) and limit of detection (LOD, expressed as IC15) of the developed assay were 3.63 mg L−1 and 0.31 μg L−1, respectively. The applicability of the developed approach was tested for detecting triazophos in incurred samples. The method showed excellent recoveries (109.6–118.9%) and relative standard deviations (RSDs) between 9.9 and 19.5%. The obtained results correlated well with those obtained by LC-MS/MS (R2= 0.9995). The competitive assay using CdSe/ZnS QDs as fluorescence-labeled probe showed good sensitivity, steady and fast response, and excellent anti-interference ability compared to conventional fluorescence-quenching methods. Finally, the feasibility of the proposed methodology was successfully applied for detection of triazophos in real samples.
研究领域:
分析化学
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食品安全
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环境科学
✓ 已验证
DOI
PubMed
高影响因子
SENSORS
·
2017
·Vol. 17
·期 1
·80
·
IF 2.677
Changwu Lv,Zhenhong Jia,Jie Lv,Hongyan Zhang,Yanyu Li
N-type macroporous silicon microcavity structures were prepared using electrochemical etching in an HF solution in the absence of light and oxidants. The CdSe/ZnS water-soluble quantum dot-labeled DNA target molecules were detected by monitoring the microcavity reflectance spectrum, which was characterized by the reflectance spectrum defect state position shift resulting from changes to the structures’ refractive index. Quantum dots with a high refractive index and DNA coupling can improve the detection sensitivity by amplifying the optical response signals of the target DNA. The experimental results show that DNA combined with a quantum dot can improve the sensitivity of DNA detection by more than five times.Keywords:N-type porous silicon;quantum dot labeling;QD-DNA;reflectance spectrum
研究领域:
材料科学
·
光学
·
生物传感
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
ACS Sensors
·
2020
·
IF 7.333
Sheng Xue,Xiao-Fang Jiang,Geng Zhang,Haiyan Wang,Zongbao Li,Xiaowen Hu,Mingyu Chen,Tianci Wang,Aiping Luo,Ho-pui Ho,Sailing He,Xiaobo Xing
For the first time, a reproducible surface plasmon-enhanced optical sensor for the detection of gaseous formaldehyde was proposed, which was fabricated by depositing a mixture of CdSe@ZnS quantum dots (QDs), fumed silica (FS), and gold nanoparticles (GNs) on the surface of a silica sphere array to meet the urgent requirement of a rapid, sensitive, and highly convenient formaldehyde detection method. Because of the spectral overlap between QDs and GNs, plasmon-enhanced fluorescence was observed in the film of QDs/FS/GNs. When exposed to formaldehyde molecules, the enhanced fluorescence was quenched linearly with the increase of formaldehyde concentration in the range of 0.5–2.0 ppm. The reason is attributed to the nonradiative electron transfer from QDs to the carbonyl of formaldehyde molecules with the assistance of amino groups. Our results demonstrate that the designed sensors are capable of detecting ultralow concentration gaseous formaldehyde at room temperature with a fast response–recovery time and excellent selectivity, stability, and reproducibility. This work provides a simple and low-cost approach for optical formaldehyde sensor fabrication and shows promising applications in environmental detection.
研究领域:
材料科学
·
环境科学
·
光学传感
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DOI
高影响因子
CHEMICAL PAPERS
·
2023
·Vol. 77
·期 7
·3703-3712
·
IF 2.2
Zhou Zhiqiang,Cen Jianfang,Wang Huixiao,Sun Yu,Yang Liyun
Due to the high importance of transferrin in targeting tumor, the investigation on the functionalization process of quantum dots (QDs) using transferrin is very essential. In this paper, the interaction between CdSe and CdSe@ZnS QDs with transferrin was studied by various spectroscopies. It was found that the two types of QDs triggered the fluorescence quenching of transferrin by the static quenching mechanism. At 298 K, the binding constant for CdSe@ZnS QDs (8.03 × 10 6 L·mol −1 ) is higher than CdSe QDs (2.84 × 10 6 L·mol −1 ), implying that CdSe@ZnS QDs could bind stronger to transferrin. In addition, the values of enthalpy change (∆ H ), entropy change (∆ S ) and Gibbs free energy change (∆ G ) were negative, indicating that the binding procedures between both QDs and transferrin were spontaneous and the main binding forces were hydrogen bonding and van der Waals force. The results of CD spectra indicated that both QDs induced the conformational change of transferrin, which further caused the release of iron ions from transferrin. Compared with CdSe QDs, less contents of iron ions in transferrin were detected after interaction with CdSe@ZnS QDs. Additional cytotoxicity tests showed that both QDs were toxic to Hela and 293T cells, but the cytotoxicity of CdSe QDs was stronger than that of CdSe@ZnS QDs. Moreover, the combination of transferrin failed to promote the cytotoxicity of CdSe QDs and CdSe@ZnS QDs, which is ascribed to the release of iron ions during the interaction process between QDs and transferrin.
研究领域:
生物化学
·
纳米医学
·
分子生物学
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产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 11
·1-8
·
IF 2.184
Chen Jun,Yang Xiao-Quan,Qin Meng-Yao,Zhang Xiao-Shuai,Xuan Yang,Zhao Yuan-Di
In this paper, polyethylene glycol-phospholipid structure is used to synthesize hybrid cluster of 40–50 nm diameter that contains hydrophobic bismuth sulfide nanoparticles and CdSe/ZnS quantum dots. The composite probe’s toxicity, CT imaging, and fluorescence imaging performance are also studied. Experimental results show that the nanocomposite hybrid cluster has obvious CT contrast enhancement and fluorescence imaging capability in vitro even after cellular uptake. It gives a CT number of 700 (Hounsfield units) at 15 mg/mL, higher than that of the current iobitridol CT contrast agent. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide experiment reveals that it has low cytotoxicity at concentration up to of 3.14 mg/mL of Bi, indicating the composite probe has potential ability for CT and fluorescence bimodal imaging.
研究领域:
医学影像学
·
纳米医学
·
生物材料学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）