SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2012
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IF 2.098
Ting-Ting Gan,Yu-Jun Zhang,Nan-Jing Zhao,Xue Xiao,Gao-Fang Yin,Shao-Hui Yu,Huan-Bo Wang,Jing-Bo Duan,Chao-Yi Shi,Wen-Qing Liu
Mercaptopropionic acid (MPA) capped CdTe quantum dots (QDs) with particle size 3 nm have been successfully synthesized in aqueous medium by hydrothermal synthesis method. And the effects of different metal ions on MPA capped CdTe QDs fluorescence were studied using fluorescence spectrometry. The results demonstrated that at the same concentration level, Ag + could strongly quench CdTe QDs fluorescence, and the other metal ions had little effect on CdTe QDs fluorescence except Cu 2+ . On the basis of this fact, a rapid, simple, highly sensitive and selective method based on fluorescence quenching principle for Ag + detection in aqueous solution was proposed. Under optimal conditions, the quenched fluorescence intensity ( F 0 – F ) increased linearly with the concentration of Ag + ranging from 4 × 10 −7 to 32 × 10 −7 mol L −1 . The limit of detection for Ag + was 4.106 × 10 −8 mol L −1 . The obtained plot of F 0 / F versus [Ag + ] was an upward curvature, concave towards the y -axis, rather than a straight line. The modified form of the Stern–Volmer equation was third order in Ag + concentration. According to the modified Stern–Volmer equation, it can be inferred that dynamic quenching and static quenching simultaneously occurred when Ag + interacted with MPA capped CdTe QDs. At the same time other factors might also influence the quenching process. Based on this study, hydrothermal synthesized MPA capped CdTe QDs with particle size 3 nm may be used as a novel fluorescence probe to quantificationally and selectively detect Ag + .
研究领域:
分析化学
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纳米材料科学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
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2017
·
IF 2.686
Jian Zhu,Zhu-Jun Zhao,Jian-Jun Li,Jun-Wu Zhao
We present a wavelength shift-based fluorescence detection method for ascorbic acid (AA) using CdTe quantum dots (QDs). Upon addition of ascorbic acid, the fluorescence emission peak of CdTe QDs red shifts linearly with the increase of the AA concentration, and the red shift speed could be improved by increasing the diameter of the QDs. The mechanism has been attributed to the AA-induced size change of the QDs. This AA-dependent red shift of fluorescence emission has been used to detect and quantify AA. Dynamic range and detection limit of this fluorescence probe are found to be 10–250 μmol/L and 1.3 μmol/L, respectively. Interference studies indicate that the AA could be specifically detected by using this wavelength shift-based fluorescence probe, and the QDs with larger diameter have better anti-interference performance. This fluorescence detection method is based on the wavelength shift of the emission peak, which is different from those reported traditional emission intensity-based fluorescent probes . Thus this fluorescence probe has the advantages of higher accuracy and convenient operation, which provides an effective strategy for design of wavelength shift-based fluorescence sensing method.
研究领域:
分析化学
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生物医学工程
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纳米技术
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DOI
高影响因子
VACUUM
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2023
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IF 4
Zhe Huang,Siyuan Wu,Baishan Chen,Siwei Tang,Yunzhu Ma,Wensheng Liu
Defects deteriorate the optical and electronic properties of the cadmium zinc telluride (CZT) single crystal . However, the growth of defects, such as vacancies and precipitation, could not be avoided in the industrial-grade preparation of CZT single crystal. Therefore, it is crucial to explore ways to eliminate defects after growth. This paper employs one-step heat treatment with the CdTe compound as an annealing atmosphere source. After annealing, some large-size Te inclusions are eliminated in CZT crystal, but nano Te precipitates still exist. At the same time, the crystal surface becomes rougher, caused by the thermal migration of Te droplets, dislocation proliferation, and aggregation. Increasing annealing time, dislocations migrate, decompose, and interact with each other to form dislocation walls, stacking faults or terminating at the surface, reducing dislocation etch pit density. In addition, a large number of ordered phases are still found in the crystal. Single annealing with CdTe significantly improved the crystal's optical and electrical properties. After 180 h annealing, the infrared (IR) transmittance of the as-grown wafer increased from 40% to 65%, and resistivity increased from 2.2 × 10 9 Ω cm to 1.7 × 10 11 Ω cm. Compared to reducing the Te precipitation phase, these increasements were mainly dominated by replacing point defects , like Cd vacancies.
研究领域:
材料科学
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半导体物理
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DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
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2015
·Vol. 15
·期 6
·4462-4469
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IF 1.556
Miao Yanping,Yang Ping,Zhao Jie,Du Yingying,He Haiyan,Liu Yunshi
CdTe quantum dots (QDs) were synthesized by 3-mercaptopropionic acid (MPA) and thioglycollic acid (TGA) as capping agents. It is confirmed that TGA and MPA molecules were attached on the surface of the QDs using Fourier transform infrared (FT-IR) spectra. The movement of the QDs in
agarose gel electrophoresis indicated that MPA-capped CdTe QDs had small hydrodynamic diameter. The photoluminescence (PL) intensity of TGA-capped QDs is higher than that of MPAcapped QDs at same QD concentration because of the surface passivation of TGA. To systemically investigate the photodegradation,
CdTe QDs with various PL peak wavelengths were dispersed in phosphate buffered saline (PBS) and Tris-borate-ethylenediaminetetraacetic acid (TBE) buffer solutions. It was found that the PL intensity of the QDs in PBS decreased with time. The PL peak wavelengths of the QDs in PBS solutions
remained unchanged. As for TGA-capped CdTe QDs, the results of PL peak wavelengths in TBE buffer solutions indicated that S2− released by TGA attached to Cd2+ and formed CdS-like clusters layer on the surface of aqueous CdTe QDs. In addition, the number of TGA on
the CdTe QDs surface was more than that of MPA. When the QDs were added to buffer solutions, agents were removed from the surface of CdTe QDs, which decreased the passivation of agents thus resulted in photodegradation of CdTe QDs in buffer solutions.
研究领域:
材料科学
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生物化学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2014
·Vol. 38
·期 9
·4519-4526
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IF 3.159
Miao Lu,Wendian Zhang,Yongkang Gai,Tan Yang,Peng Ye,Guang Yang,Xiang Ma,Guangya Xiang
Fluorescent probes based on quantum dots (QDs) are emerging as ideal tools for sensing and imaging in biological applications owing to their great advantages such as high sensitivity and unique optical properties. Using QDs as potential effective tools for tumor optical imaging would allow early diagnosis, monitoring of tumor progression and treatment efficiency. We prepared a novel folate receptor-targeted, PEG-modified fluorescent probe based on silica-coated CdTe QDs. In the study, the hydrophilic thioglycolic acid stabilized CdTe QDs were directly synthesized in the water phase; the water-in-oil (W/O) reverse microemulsion method was applied to prepare the highly fluorescent amino-functionalized core–shell CdTe@SiO2 particles; subsequently, polyethylene glycol (PEG) and folate molecules were successfully bioconjugated with the CdTe@SiO2 particles through the amino groups. The as-prepared particles were characterized by UV-Vis absorption, fluorescence measurements, particle size, zeta potential and high-resolution transmission electron microscopy (HR-TEM). The bioimaging efficiency and specificity of the prepared fluorescent probes were further evaluated on KB cells. Results indicate that the silica film encapsulated and PEGylated CdTe QDs can significantly reduce the cytotoxicity of CdTe QDs. In conclusion, folate receptor-targeted, PEG-modified and silica-coated CdTe quantum dot fluorescent probes are highly promising for tumor imaging in the near future.
研究领域:
生物医学
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材料科学
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纳米技术
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2018
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IF 2.732
Jian Zhu,Si-Nan Wang,Jian-Jun Li,Jun-Wu Zhao
In this work, the effect of core size on the fluorescence emission properties of CdTe@CdS core@shell quantum dots was investigated under the condition of different shell thickness and pH values. Both CdTe and CdTe@CdS core@shell QDs were synthesized in aqueous phase by a simple method, whose optical features were characterized by absorption and fluorescence spectra . High resolution transmission electron microscopy (HRTEM) and X-Ray Diffraction (XRD) were utilized to study the structure and composition of the as-prepared QDs. We can conclude that a smaller initial core exhibits a greater potential for optimizing both fluorescence intensity enhancement and red shift. What's more, there is an optimal shell thickness for the strongest fluorescence intensity while a thicker shell contributes to a larger fluorescence red shift. The optimal pH value is 10.5 for the fluorescence intensity enhancement of the core@shell QDs and a higher pH value is an advantage to expedite the growth rate of CdS shell.
研究领域:
材料科学
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光学
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DOI
高影响因子
Integrative Biology
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2012
·Vol. 4
·期 3
·301-309
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IF 4.509
Ni Xiaoling
People exposed to engineered nanomaterials have potential health risks associated. Human α-amylase is one of the key enzymes in the digestive system. There are few reports about the influence of quantum dots (QDs) on the digestive enzymes and their inhibition system. This work focused on the toxic effect of CdTe/CdSe QDs on the interactions between α-amylase and its natural inhibitors. Thirty-six dietary polyphenols, natural α-amylase inhibitors from food, were studied for their affinities for α-amylase in the absence and presence of CdTe/CdSe QDs by a fluorescence quenching method. The magnitudes of apparent binding constants of polyphenols for α-amylase were almost in the range of 105–107 L mol−1 in the presence of CdTe/CdSe QDs, which were higher than the magnitudes of apparent binding constants in the absence of CdTe/CdSe QDs (104–106 L mol−1). CdTe/CdSe QDs obviously improved the affinities of dietary polyphenols for α-amylase up to 389.04 times. It is possible that the binding interaction between polyphenols and α-amylase in the presence of CdTe/CdSe QDs was mainly caused by electrostatic interactions. QDs significantly influence the digestive enzymes and their inhibition system.
研究领域:
生物化学
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毒理学
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食品科学
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DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2021
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IF 1.134
Xia-Chu-Qin LI,Tong YANG,Jian WANG,Cheng-Zhi HUANG
In this work, electrospun nanofibers (NFs) with good moisture-resistance were prepared by electrospinning technology, and further assembled with CdTe quantum dots (CdTe QDs). The results of scanning electron microscopy, transmission electron microscopy and confocal fluorescence microscopy showed that the CdTe QDs with strong fluorescence were uniformly assembled on the surface of electrospun NFs after the electrostatic adsorption for 90 min at pH 7.2. Under 365 nm excitation, the CdTe QDs-NFs assembly presented red fluorescence, which could be significantly quenched by copper ion (Cu 2+ ), and the fluorescence quenching degree of CdTe QDs-NFs assembly showed a good linear relationship with Cu 2+ concentration in the range of 0.08–800 μmol/L, and the detection limit was 11.1 nmol/L. This method had advantages of simplicity and high selectivity, and was successfully applied to the visualization and portable detection of Cu 2+ in environmental water samples.
研究领域:
材料科学
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环境科学
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分析化学
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DOI
高影响因子
JOURNAL OF INORGANIC BIOCHEMISTRY
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2018
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IF 3.063
Min Wang,Xiaofang Fei,Shaowu Lv,Ye Sheng,Haifeng Zou,Yanhua Song,Fei Yan,Qianlong Zhu,Keyan Zheng
In this study, we designed and synthesized two novel fluorescent magnetic nanoparticles . Fe 3 O 4 @SiO 2 -NH-GSH-CdTe (FSGC) (GSH = glutathione) nanoparticles were synthesized using amino-functionalized Fe 3 O 4 @SiO 2 nanoparticles and GSH-stabilized CdTe quantum dots (CdTe QDs), while flexible Fe 3 O 4 @SiO 2 -NH-GSH-CdTe-NH-NH 2 (FSGCN) nanoparticles were synthesized using the FSGC precursor and 1,6-hexamethylenediamine. These two kinds of nanoprobes exhibited excellent magnetic and fluorescent properties. By comparing the fluorescence quenching effect of folic acid (FA) on FSGC and FSGCN, we found that the quenching effect of FA on FSGC was acute and the process was too fast to determine the FA content. However, the quenching effect of FA on flexible FSGCN was mild and hence it could be used as a nanoprobe to determine FA concentration. At physiological pH, the fluorescence quenching effect of FA on the FSGCN nanoprobes was fitted according to the Stern–Volmer equation with a linear response in the concentration range of 0.14 to 4.20 μg mL −1 with a detection limit of 15.1 × 10 −9 g mL −1 (S/N = 3) under optimized experimental conditions. The proposed flexible nanoprobe was successfully used to determine the content of FA in folic acid tablets. Recovery was found to be in the range of 92.7%–105.6% with a relative standard deviation of 1.12%–3.84%. Owing to their good stability, environment-friendly characteristics, high selectivity, and good optical properties and biocompatibility, these nanoprobes have potential for usage in practical applications.
研究领域:
生物医学工程
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分析化学
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DOI
PubMed
高影响因子
RSC Advances
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2015
·Vol. 5
·期 70
·57082-57089
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IF 3.84
Ying Zhang,Baozhu Hu,Yuming Huang
The use of engineered nanoparticles would increase their release into wastewater treatment plants, leading to the risk of contaminating water and ultimately causing environmental and health concerns. The removal of such nanoparticles from wastewater is highly needed. In this text, the polyethyleneimine (PEI)-decorated grapefruit peel (GP) composite adsorbent was facilely prepared for this purpose, which was based on PEI grafting onto the GP through a simple one-step reaction. The as-prepared PEI–GP adsorbent was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectrometry (XPS), showing that PEI was successfully grafted onto GP. The as-prepared PEI–GP adsorbents were used for the removal of CdTe quantum dots (QDs). Batch adsorption experiments were performed to investigate the influences of pH, contact time, initial CdTe QDs concentration, ionic strength and humic acid concentration. The results show that the adsorption kinetics could be fitted well to the pseudo-second-order model and the adsorption process could be described well by the Freundlich adsorption isotherm. The ionic strength caused a significant effect on the adsorption of CdTe QDs onto the PEI–GP adsorbents due to aggregation of the CdTe QDs in the presence of salt. The presence of humic acid had a minor effect on the sequestration of CdTe QDs by the PEI–GP biosorbents. The results indicate that the PEI–GP composite can be used as a promising adsorbent for the removal of CdTe QDs from aqueous media.
研究领域:
环境科学
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材料科学
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纳米技术
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DOI
高影响因子
LUMINESCENCE
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2015
·Vol. 30
·期 7
·1112-1118
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IF 1.518
Chenxia Hao,Shaopu Liu,Dan Li,Jidong Yang,Youqiu He
A sensitive and simple analytical strategy for the detection of sodium cromoglycate (SCG) has been established based on a readily detectable fluorescence quenching effect of SCG for glutathione-capped (GSH-capped) CdTe quantum dots (QDs). The fluorescence of GSH-capped CdTe QDs could be efficiently quenched by SCG through electron transfer from GSH-capped CdTe QDs to SCG. Under optimum conditions, the response was linearly proportional to the concentration of SCG between 0.6419 and 100 µg/mL, with a correlation coefficient ( R ) of 0.9964; the detection limit (3δ/K) was 0.1926 µg/mL. The optimum conditions and the influence of coexisting foreign substances on the reaction were also investigated. The very effective and simple method reported here has been successfully applied to the determination of SCG in synthetic and real samples. It is believed that the established approach could have good prospects for application in the fields of clinical diseases diagnosis and treatment. Copyright © 2015 John Wiley & Sons, Ltd.
研究领域:
分析化学
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药物分析
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生物医学
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DOI
PubMed
高影响因子
TALANTA
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2016
·
IF 4.035
Chunli Jiang,Zhitao Shen,Chunhua Luo,Hechun Lin,Rong Huang,Yiting Wang,Hui Peng
A facile one-pot strategy has been developed for the aqueous synthesis of Gd doped CdTe (Gd:CdTe) QDs as fluorescence and magnetic resonance imaging dual-modal agent. The prepared Gd:CdTe QDs showed narrow size distribution and the average size was less than 5 nm. The amount of Gd 3+ dopant in Gd:CdTe QDs significantly affected the optical properties of obtained QDs. The highest PL QY for the prepared Gd:CdTe QDs was up to 42.5%. The QDs showed the weak toxicity and significant enhancement in MRI signal. The specific relaxivity value ( r1 ) was determined to be 4.22 mM −1 s −1 . These properties make the prepared Gd:CdTe QDs be an effective dual-modal imaging agent and have great potential applications in biomedical field.
研究领域:
材料科学
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医学影像
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纳米生物学
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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）