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).
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高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 7
·1527-1534
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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.
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高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Chunxiao Qiu,Youhong Xing,Wenming Yang,Zhiping Zhou,Yingchun Wang,Hong Liu,Wanzhen Xu
Twenty molecular dynamics (MD) simulations of molecular imprinting prepolymerization systems had been performed to optimize the imprinting shell of the fluorescent sensor. The results revealed that the system with a Bisphenol A (BPA): 3-aminopropyltriethoxysilane (APTES): tetraethylorthosilicate (TEOS) mole ratio of 10:15:60 had the most stable template (T)-functional monomer (FM) cluster. Correspondingly, five kinds of imprinted and non-imprinted polymers were synthesized to assess the reliability and validity of the simulation results. Hybrid SiO 2 -coated CdTe NCs (HS-QD) were synthesized by a simple reflux procedure including a sol-gel reaction that resulted in the formation of a hybrid SiO 2 layer with CdS-like clusters on a CdTe core. Based on the optimal component ratio of the prepolymerization system, MIP shells were anchored on the surface of HS-QD to build a fluorescent MIP sensor. A linear relationship between relative fluorescence intensity and the concentration of BPA had been obtained covering the concentration range of 0.05–10 μmol L −1 with a limit of detection of 6 nmol L −1 . The feasibility of the fluorescent sensor was successfully evaluated through the analysis of BPA in river water and milk. The recoveries are above 96.31%, and the relative standard deviation (RSD) ranged from 1.55% to 2.78%.
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高影响因子
SPECTROSCOPY LETTERS
·
2014
·
IF 0.718
Rui-Yong Wang,Jing Wu,Lv-Jing Wang,Rui Wang,Huan-Jing Dou
Water-soluble and stable CdTe quantum dots were synthesized in aqueous solution with thioglycolic acid as the stabilizer. A spectrofluorometric method for the determination of iron (II) has been developed based on quenching of the fluorescence of CdTe quantum dots by iron (II) in aqueous solutions. It can perform an accurate and simple determination of iron (II) concentration in water samples. Under optimum conditions, the quenched fluorescence intensity increased linearly with the concentration of iron (II) ranging from 5.0 × 10−8 to 4.0 × 10−6 mol/L with a correlation coefficient R = 0.9969. The limit of detection for iron (II) was found to be 1.2 × 10−8 mol/L. As an application, the proposed method was successfully applied to the analysis of iron (II) in water samples, and the results were satisfactory.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2014
·Vol. 38
·期 9
·4519-4526
·
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.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Xiao Wei,Guodan Xu,Chengcheng Gong,Fang Qin,Xinghui Gong,Chen Li
In this paper, we have presented a custom-tailored strategy to fabricate molecularly imprinted composite sensors (MIPs/QDs@SiO 2 ) with highly selective recognition ability for the determination of sulfanilamides (SAs). The modified SiO 2 sphere, modified QDs, acrylamide (AM), and ethyl glycol dimethacrylate (EGDMA) were used as the supporter, the fluorescent material, the functional monomer , and the cross-linker, respectively. Afterward, a two-step imprinting polymerization reaction was implemented to fabricate the novel sensor MIPs/QDs@SiO 2 . Attributing to the SiO 2 with the surface functional monomer and the QDs with functional group, SAs molecules are attracted to the QDs and bound to the SiO 2 surface, hence accelerating the growth of homogeneous recognition sites on the surface of SiO 2 and guaranteeing the distance between the recognition sites and the QDs. After the experimental conditions were optimized, such fluorescence sensors can be used for well selective detection of SAs with a linear range of 2.0–30 μmol/L and a limit of detection is 0.17 μmol/L. Most importantly, the MIPs/QDs@SiO 2 can be successfully applied to the determination of SAs in real river water, which demonstrate high selectivity and stability and offer a promising platform for detecting environmental pollutants.
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Polymer Chemistry
·
2017
·Vol. 8
·期 31
·4520-4527
·
IF 5.375
Lu Wang,Wencong Wang,Wei Cao,Huaping Xu
Nanomaterials with hierarchical responsiveness are of great significance not only for fundamental science but also for future biomedical applications due to sophisticated and hierarchical physiological environments. Herein, we report a selenium- and tellurium-containing block copolymer that can be stepwise oxidized by both chemical methods and electrochemical methods. Differences in sensitivity to the oxidation of selenium and tellurium were employed. By tuning the concentration of the oxidant and oxidation periods, self-assembly behaviors of the copolymer were tuned by stepwise chemical oxidation. After oxidation, some interesting morphological evolution was observed that the polymer micelles crosslinked with each other without any swelling. In the case of electrochemical oxidation, the voltage during the electrochemical oxidation and the oxidation period also affected the level of oxidation. Furthermore, we showed that the degree of electrochemical oxidation varied with a different PEG block length. Considering sophisticated physiological conditions in vivo, this hierarchically responsive system may provide new possibilities as smart delivery vehicles in biological environments.
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高影响因子
BIOMATERIALS
·
2017
·
IF 8.402
Feng Li,Tianyu Li,Wei Cao,Lu Wang,Huaping Xu
Cisplatin (CDDP) has received worldwide approval for clinical use in the past decades. However, its development in cancer chemotherapy was overshadowed by severe side effects and drug resistance. Herein, we developed a CDDP drug delivery system with high encapsulation efficiency and near-infrared light stimuli-responsive drug release properties based on the coordination of novel tellurium-containing block polymer (PEG-PUTe-PEG) and CDDP. The nanocarriers made from PEG-PUTe-PEG were loaded with CDDP and indocyanine green (ICG) simultaneously. The coordination chemistry between CDDP and tellurium guaranteed the nanocarrier a high stability in plasma and prolonged circulation time in vivo by reducing possible penetration of water molecule into the nanoparticles . Under the stimuli of a near-infrared laser, an amount of ROS can be generated by irradiation of ICG. The tellurium is easily oxidized by ROS because of the low electronegativity of tellurium. The CDDP could be rapidly released from the nanocarriers along with the oxidation of the tellurium at the tumor sites as the oxidized tellurium will weaken the coordination interaction with CDDP. In addition, the encapsulated ICG played a synergistic antitumor effect through photothermal effect with mild laser irradiation . The integrated strategy achieved higher antitumor efficacy and showed minimal side effects compared with the CDDP alone.
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Xiao Zhang,Yiming Zhou,Yanling Pei,Yuexing Chen,Bifei Yuan,Shuangmei Zhang,Yuan Deng,Shengkai Gong,Jiaqing He,Li-Dong Zhao
SnTe, one lead-free analogue of PbTe, has been paid attention in thermoelectric community because it has the similar rock-salt crystal structure and electronic band structure . However, SnTe possesses a very high total thermal conductivity (∼10.0 W m −1 K −1 at room temperature) and a mediocre ZT (∼0.2 at 723 K). In this study, to reduce its thermal conductivity, we prepare SnTe samples by melting reaction followed by mechanical alloying and spark plasma sintering . We demonstrate that both total thermal conductivity and lattice thermal conductivity can be considerably reduced through reducing particle size from micro-scale to nano-scale via facially mechanical alloying method. Experimental results show that the total thermal conductivity at room temperature can be reduced from ∼10 W m −1 K −1 for SnTe ingot to ∼3Wm −1 K −1 for SnTe with mechanical alloying 25 h. Correspondingly, the lattice thermal conductivity at room temperature was reduced from ∼5Wm −1 K −1 to ∼2Wm −1 K −1 . Combination of reduced thermal conductivity and moderate power factor, average ZT ave can be increased by 33.3%, from 0.09 for SnTe ingot to 0.12 for SnTe with nano-grain size.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 100
·期 12
·5723-5730
·
IF 2.841
Zhiwei Zhou,Junyou Yang,Qinghui Jiang,Dan Zhang,Jiwu Xin,Xin Li,Yangyang Ren,Xu He
In this work, the thermoelectric properties of SnTe have been regulated synergistically by introduction of n -type ZnO nanoinclusions. On one hand, the excessive holes in SnTe matrix were compensated properly by n -type ZnO, and the Seebeck coefficient has been improved greatly due to the carrier energy filtering effect by a large quantity of ZnO-SnTe hetero-junction interface barriers; On the other hand, the thermal conductivity gets reduced by the enhanced phonon scattering from multiscale hierarchical architectures. Consequently, a maximum ZT of ~0.9 at 873K has been obtained in the 0.8 wt% sample, which enhances by 112% in comparison with the nanoinclusion-free sample.
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高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 6
·929-936
·
IF 1.9
Fan Zhang,Miaomiao Chen,Haiqing Zhang,Huayu Xiong,Wei Wen,Xiuhua Zhang,Shengfu Wang
A sensitive, convenient and rapid fluorescent sensor for effectively and directly detecting propranolol was proposed based on the fluorescence suppression of 3-mercaptopropionic acid stabilized CdTe quantum dots. The fluorescence suppression mechanism between CdTe QDs and propranolol was studied by time-resolved fluorescence spectroscopy, UV-Vis spectroscopy and fluorescence spectroscopy, and it was attributed to the simultaneous action of the inner filter effect (IFE) and dynamic quenching effect (DQE). The effects of the concentration of quantum dots, pH value of buffer solution and incubation time on the fluorescence signal of the propranolol/CdTe quantum dot system were also investigated. The results indicated that, when the experiment was conducted under optimal experimental conditions, the linear range of this assay was 0.1 μM to 2 μM and 5 μM to 200 μM, with a corresponding detection limit of 0.055 μM. Moreover, some common drug excipients and analogues of propranolol and stimulants had no apparent effect on the determination of propranolol. The proposed fluorescent sensor could be readily used for effectively and directly detecting propranolol in biological samples.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Tongfan Hao,Xiao Wei,Yijing Nie,Yeqing Xu,Kai Lu,Yongsheng Yan,Zhiping Zhou
In this work, 3-aminophenylboronic acid (APBA) functionalized dual-emission quantum dots (QDs) were prepared and utilized as the ratiometric fluorescence probe for the onsite naked eye determination of glucose. The unique ratiometric fluorescence probe, which combined ratiometric fluorescence technique with boric acid functional materials into one system, has been prepared by hybridizing red-emitting CdTe QDs (r-QDs) and green-emitting CdTe QDs (g-QDs). The fluorescence of the embedded r-QDs stays constant, whereas the g-QDs functionalized with APBA can selectively bind glucose by the chemistry of boronic acid and cis diol compounds, leading to the fluorescence of g-QDs quenched due to the surface quenching states induced mechanism and resulting in continuous fluorescence color changes (from green to red) of the ratiometric fluorescence probe system. Under optimum conditions, the proposed ratiometric probe was used for selective detection of glucose in a concentration range of 0.1–2.0 mmol/L with a detection limit of 4.5 μmol/L. Moreover, the developed ratiometric fluorescence probe was successfully applied to the detection of glucose in human serum samples. The present study provides an efficient and facile ratiometric fluorescence probe for rapid, convenient, sensitive and selective visual identification of glucose in blood glucose sensing without the need of complex equipment.
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高影响因子
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