SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2020
·
IF 3.232
Meiling Ding,Kun Wang,Min Fang,Weiju Zhu,Longchao Du,Cun Li
Mercaptopropionic acid (MPA) capped CdTe quantum dots (MPA-CdTe QDs) were synthesized in aqueous medium by hydrothermal method , which modified by Fe 3+ could be used as a fluorescent probe to detect ascorbic acid (AA). MPA-CdTe QDs fluorescence probe could be used as successive sensor for metal ions and AA with “on-off-on” process. The fluorescence of QDs was quenched after adding Fe 3+ to MPA-CdTe QDs. Then, the fluorescence of the Fe 3+ @MPA-CdTe QDs can be sensitively turned on by AA to give an “on–off–on” fluorescence response according to the oxidation–reduction between Fe 3+ and AA. There was a linear relationship between fluorescence intensity quenching value and the concentration of Fe 3+ in the range of 2–10 μM since Fe 3+ sensitively reacted with CdTe QDs. The linear detection range for AA was 0.1–1 μM with a limit of detection of 6.6 nM. The principle is proved by fluorescence emission spectroscopy, nuclear magnetic resonance spectroscopy. The proposed method is successfully used to detect the AA in human plasma sample.
研究领域:
分析化学
·
生物化学
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DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Chen Wanqiu,Chen Ting,Fang Min,Zhu Weiju,Li Cun
In this work, a simple and sensitive N-acetyl-L-cysteine (NAC)-covered CdTe quantum dots (NAC-CdTe QDs) fluorescence probe for continuous detection of Co 2+ and pyrophosphate ions (PPi, P 2 O 7 4− ) was synthesized. The fluorescence of the quantum dots was significantly quenched by Co 2+ through the coordination of Co 2+ and the carboxyl groups on the NAC-CdTe quantum dots. Interestingly, the combination of NAC-CdTe quantum dots with Co 2+ yields a new fluorescence probe of Co 2+ -modified NAC-CdTe QDs (Co 2+ @NAC-CdTe). The addition of PPi restored the fluorescence due to the competition between PPi and carboxyl groups with Co 2+ causing Co 2+ to detach from the surface of Co 2+ @NAC-CdTe quantum dots. Thus, a sensitive and reversible detection of Co 2+ and PPi had been successfully established. The Co 2+ @NAC-CdTe quantum dots fluorescence probe exhibits excellent selectivity and high sensitivity toward PPi detection with low detection limit of 0.28 μM. In addition, the novel fluorescence probe was successfully applied to detect the concentration of PPi in environmental water samples and in-vitro cells imaging.
研究领域:
分析化学
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生物医学工程
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DOI
PubMed
高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 10
·2226-2232
·
IF 1.915
Linye Jiang,Haijian Liu,Ming Li,Yue Xing,Xueqin Ren
We tested a simple and economical approach to synthesize CdTe quantum dots (QDs). We then developed a MIP-capped CdTe QD fluorescent sensor by anchoring a molecularly imprinted polymer (MIP) layer on the surface of CdTe QDs using 3-aminopropyltriethoxysilane as the functional monomer and tetramethoxysilane as the cross-linker via a surface molecular imprinting process. The sensor possessed the sensitivity of CdTe QDs, the selectivity of the molecular imprinting technique, and a nearly spherical morphology. The fluorescence of the MIP-capped CdTe QDs can be efficiently quenched when the template 4-nitrophenol (4-NP) rebinds to the binding sites, as a result of the charge transfer from QDs (donor) to 4-NP (acceptor). MIP-capped CdTe QDs generated a significantly reduced fluorescence intensity within the initial 12 min of binding 4-NP. Under optimized conditions, the sensor presented a satisfactory linearity with 4-NP concentrations in the range of 1–30 μM, and the detection limit was 40 nM. The sensor also successfully detected trace amounts of 4-NP in water samples, and the recovery of 4-NP in three spiked samples ranged from 95.1% to 98.1% with relative standard deviations below 4.3%. The results provide an alternative method for the development of sensors for the rapid recognition and determination of 4-NP in water samples.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
ACS Applied Nano Materials
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2020
·
IF 0
Yun Shan,Hong-Lin Zhang,Yuan Zhu,Ying Wang,Huaju Song,Chuanguo Shi
An electrochemiluminescent immunosensor is constructed for the detection of diethylstilbestro (DES) on the basis of amplified quenching of electrochemiluminescence (ECL) from CdTe nanocrystal (NC)/reduced graphene oxide (rGO) composite films by antibody (Ab) against DES-modified SiO2 nanoparticles (Ab@SiO2). In this immunosensing system, CdTe NC/rGO composite films act as solid supporters for both DES and ECL emitters, which generate a 100-fold stronger ECL emission than CdTe NC films because the presence of rGO can lower the potential barrier, facilitate charge transfer, suppress nonradiative Auger recombination, and make the electron trap states fill more efficiently. On the composite films, the immobilized ovalbumin-modified DES (OVA-DES) competes with free target DES to bind Ab@SiO2. As a result, the number of formed OVA-DES-Ab@SiO2 immunocomplexes is inversely related to that of target DES. Using an ECL quenching maximum at blank as a calculation benchmark, the ECL intensity increment of the immunosensor and the concentration of target DES show a linear range of 0.002–2 ng/mL (R2 = 0.996) with a detection limit of 0.001 ng/mL (signal/noise = 3). This immunosensor, of good selectivity and stability, was used to detect beef samples, with recoveries at a scope of 93.2%–105.0%.
研究领域:
分析化学
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生物医学工程
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DOI
JOURNAL OF LUMINESCENCE
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2013
·
IF 2.144
Huilin Tao,Xiufen Liao,Mingze Xu,Shuhuai Li,Fuxin Zhong,Zhongsheng Yi
The fluorescence resonance energy transfer between fluorescent brightener (FB, donor) and CdTe quantum dots (CdTe QDs, acceptor) was studied and a new method for detecting Hg 2+ ions in water samples was accordingly developed in this paper. It was found that the effective energy transfer occurred from FB to CdTe QDs in Tris–HCl buffer solution at pH=8.2, in which the QDs' fluorescence intensity increased greatly. Then the fluorescence quenching occurred as Hg 2+ interacted with CdTe. Under the optimized conditions, there was a linear relationship between the fluorescence quenching intensity and the concentration of Hg 2+ . Hg 2+ could be determined in the concentration range of 8.0×10 −9 –8.0×10 −7 g L −1 with a detection limit of 6.6×10 −10 g L −1 ( S / N =3). The method was applied to the determination of Hg 2+ in water samples via the standard addition method, and the recovery rate obtained was 97.3–105.5%.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2019
·
IF 6.393
Xiqing Liu,Tao Wang,Yang Lu,Wenjuan Wang,Zhiping Zhou,Yongsheng Yan
The sensitive monitoring and rapid removal antibiotics residues are great challenges and hugely significant for the environmental protection. In this work, a green and facile strategy was obtained for the fabrication of highly fluorescent carbon dots (CDs) through hydrothermal treatment of osmanthus fragrans leaves as carbon source and polyethyleneimine as nitrogen source. Then the prepared blue CDs were combined with red CdTe quantum dots (QDs) for constructing MIPs@CdTe/CDs@SiO 2 was applied to selectively and sensitively assay ciprofloxacin (CIP) and TiO 2 /CDs/CdTe QDs as photocatalyst for the degradation of CIP. Under optimum conditions, MIPs@CdTe/CDs@SiO 2 has exhibited lower detection limit of 0.0127 nM with the linear range of 0–60 nM, and successfully applied to monitor CIP in human urine samples. Moreover, the TiO 2 /CDs/CdTe QDs also displayed good photocatalytic degradation of activity to CIP under sunlight irradiation. This present work which was rational constructed materials based on CDs and CdTe QDs illustrates the great practicability and potential to rapid and efficient determination and removal environmental pollutants in the future.
研究领域:
环境科学
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材料科学
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分析化学
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DOI
高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2014
·Vol. 29
·期 5
·633-640
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IF 1.815
Jun Yao,Mei Yang,Yixiang Duan
Highly luminescent CdTe quantum dots (QDs) were prepared through a fast, facile, and straightforward method. The crystal structure, particle size, optical properties as well as molecular interactions between the CdTe QDs and their capping agents have been investigated by high resolution transmission electron microscopy, selected area electron diffraction, scanning transmission electron microscope–energy dispersive x-ray spectroscopy, UV-vis absorption, photoluminescence, and Fourier transform infrared, respectively. The results illustrate that the CdTe nanoparticles exhibit cubic structure and the average crystallite size is 2.3 nm. Meanwhile, fluorescence and UV-vis spectroscopic techniques were used to study the interaction between hemin and the well-defined CdTe QDs. In weak basic media, the fluorescence of CdTe QDs was quenched notably by hemin, and the quenching values were proportional to the concentration of the quencher in a certain range. The quenching mechanism was discussed to be a dynamic quenching procedure, collisional process, and hemin as a fluorescence quencher donated its electron to CdTe QDs to occupy the hole and accordingly disrupted the electron–hole recombination.
研究领域:
纳米材料科学
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生物分析化学
·
光学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 7
·1527-1534
·
IF 3.741
Wei Xiao,Zhou Zhiping,Hao Tongfan,Xu Yeqing,Li Hongji,Lu Kai,Dai Jiangdong,Zheng Xudong,Gao Lin,Wang Jixiang,Yan Yongsheng,Zhu Yanzhuo
A molecularly imprinted polymer (MIP) was deposited on the surface of CdTe quantum dots (QDs) to act as a recognition element for aspirin. The MIP was synthesized from 3-aminopropyltriethoxysilane as the functional monomer, aspirin as the template, and tetraethoxysilane as the cross-linker via a sol–gel process that leads to surface imprinting. It is shown that the fraction of QDs and the polymerization process affect size and morphology of the MIP-coated QDs. The optical stability, effects of pH, detection time and selective determination of aspirin were optimized. The fluorescence intensity of the particles (photoexcited at 400 nm and measured at 628 nm) decreases linearly with increasing concentration of aspirin in the 2.0–50 μmol L −1 range. The limit of detection (at an S/N of 3) is 0.25 μmol L −1 . The method was successfully applied to the determination of aspirin in human urine and saliva.
CdTe quantum dots, APTES (the functional monomer), aspirin (the template) and TEOS (the cross-linker) were copolymerized to form a surface-imprinted polymeric network around the template. After extraction of the template, the imprint-coated quantum dots are capable of specifically recognizing aspirin.
研究领域:
分析化学
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材料科学
·
药物分析
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DOI
高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 183
·期 2
·581-588
·
IF 3.741
Rao Hanbing,Liu Wei,Lu Zhiwei,Wang Yanying,Ge Hongwei,Zou Ping,Wang Xianxiang,He Hua,Zeng Xianying,Wang Yongjia
The surface of CdTe quantum dots (Q-dots) was modified with thioglycolic acid (TGA) and these Q-dots were then covalently conjugated to amino-functionalized silica-coated carbon dots (C-dot@SiO 2 ) via carbodiimide chemistry. The Q-dots form kind of “satellites” on the surface of the C-dot@SiO 2 nanoparticles. The nanoparticle conjugates display dual emission (with peaks at 441 nm and 605 nm) under UV excitation and were further characterized by transmission electron microscopy, UV–vis absorption and FTIR spectroscopy. The C-dot@SiO 2 @Q-dots hybrid spheres are shown to represent a ratiometric fluorescent probe for Cu 2+ in that the emission of the Q-dots is quenched by Cu 2+ , while the emission of the C-dots (which are coated with SiO 2 ) is not quenched. The ratio of the fluorescence intensities at 441 and 655 nm is related to the concentration of Cu 2+ in the range from 0.1 to 1.0 μM, with a 0.096 μM lower detection limit. The ratiometric probe was successfully applied to the determination of Cu 2+ in (spiked) vegetable and fruit samples by the standard addition method, and recoveries ranged from 96.7 to 100.8 %.
Carbon dots were first coated with silica and then with CdTe quantum dots to give nanoparticles with an architecture of the type C-dot@SiO 2 @Q-dots. These are shown to be a viable ratiometric fluorescent probe for the detection of Cu(II).
研究领域:
分析化学
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材料科学
·
环境科学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Yawen Guo,Xuesong Ge,Jing Guan,Lin Wu,Fuhua Zhao,Hui Li,Xindong Mu,Yijun Jiang,Aibing Chen
A method was presented for fabricating the fluorescent nanocomposites containing CdTe quantum dots (QDs) and montmorillonite (MMT)-chitosan (CS). MMT-CS/CdTe QDs nanocomposites were prepared via a simple, versatile and robust approach combination of covalent and electrostatic assembly methods (Scheme 1). The negatively charged MMT was initially modified with positively charged CS through electrostatic assembly, followed by incorporation of CdTe-QDs into the MMT-CS nanosheets by covalent connections between the amino groups of CS and the carboxylic acid groups of thioglycollic acid (TGA). The X-ray diffraction (XRD), High resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the FTIR were used to prove the QDs have intercalated into the MMT-CS matrix. The fluorescence emission spectra showed that the MMT-CS/CdTe QDs nanocomposites had the best fluorescence intensity compared with the bare CdTe QDs and CS-QDs.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
FOOD CONTROL
·
2023
·
IF 6
Jinxiang Wei,Yifei He,Zhiyi Song,Imran Mahmood Khan,Zhouping Wang,Caiyun Jiang,Xiaoyuan Ma
Herein, a surface-enhanced Raman scattering (SERS) and fluorescence dual-signal aptasensor has been developed for aflatoxin B 1 (AFB 1 ) detection. Fluorescence signal source CdTe quantum dots were decorated on the outer of silica nanoparticles and further functionalized with AFB 1 aptamer. Raman reporter molecules DTNB were decorated on the surface of gold nanoparticles (AuNPs) together with the aptamer complementary chains. The two parts of nanomaterials were combined by the base complementary pairing principle, to form satellite nanostructures with high SERS and low fluorescence signals following LSPR and FRET effect. The addition of AFB 1 led to the shedding of AuNPs due to the higher sensitivity of the aptamer towards the target and resulting in recovered fluorescence and decreased SERS signals. The developed method showed a linear relationship in the range of 10 −4 -10 3 ng/mL, with detection limit of 0.094 pg/mL. This technology had strong application prospects due to simplicity of operation and high accuracy.
研究领域:
分析化学
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食品安全
·
纳米技术
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产品关联
DOI
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 36
·5339-5347
·
IF 1.9
Ke Huang,Rui Dai,Wenqing Deng,Ling Lin,Ai Zhang,Xin Yuan
A novel visual detection method was developed for silver using CdTe quantum dot (QD) immobilized paper. CdTe QDs were synthesized in aqueous solution by hydride generation (HG) for the first time, with H2Te gas being introduced into the aqueous medium containing Cd2+ ions. The gaseous precursor, H2Te, is generated on-line by reducing TeO32− with KBH4. The visible fluorescence from the CdTe QDs immobilized on paper was quenched by Ag+. A limit of detection (LOD) of 0.01 μg mL−1 and a relative standard deviation (RSD, n = 7) of 2.1% at a concentration of 1 μg mL−1 of Ag+ were obtained when using a commercial fluorescence spectrophotometer as the detector. In visual detection, as low as 1 μg mL−1 of Ag+ in antibacterial textiles and drugs can be easily discriminated from the blank with the naked eye. The proposed method has several unique advantages, including straightforwardness, rapidness, affordability and requirement of no equipment for visual detection.
研究领域:
分析化学
·
纳米技术
·
环境科学
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产品关联
DOI
高影响因子
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