NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 41
·17984-17992
·
IF 3.288
Guoning Chen,Qianqian Hu,Hua Shu,Lu Wang,Xia Cui,Jili Han,Kamran Bashir,Zhimin Luo,Chun Chang,Qiang Fu
The sensing method for hydrogen peroxide could also be employed to detect H2O2-bioprecursors in the presence of oxidase. However, the sensitivity of the conventional method is limited, and the catalytic stability and recyclability of enzymes also need to be improved. In this study, glucose was chosen as a typical representative H2O2-bioprecursor to design a fluorescence sensing system for H2O2-bioprecursors based on a magnetic immobilized enzyme and CdTe quantum dots. The magnetic immobilized enzyme was fabricated by a cross-linking method to enhance the stability and recyclability of the enzyme. The obtained product was characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometry, and vibrating sample magnetometry, respectively. The CdTe quantum dots were prepared by a hydrothermal method, and revealed a maximum emission peak at about 610 nm under the maximum excitation light (339 nm). The developed CdTe QDs exhibited excellent sensing performance for hydrogen peroxide. The prepared immobilized enzyme and quantum dots were used to develop a fluorescence sensing system and were successfully exploited to detect a typical H2O2-bioprecursor (glucose) in the presence of glucose oxidase. The method exhibited good linear performance in the concentration range of 1–20 μg mL−1, and good recoveries ranging from 106.2–117.7%. This study demonstrated that the strategy could be extended to detect more H2O2-bioprecursors.
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APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Li Wang,Daqing Yu,Baoquan Huang,Ziyuan Ou,Li Tao,Lili Tao,Zhaoqiang Zheng,Jun Liu,Yibin Yang,Aixiang Wei,Yu Zhao
Two-dimensional (2D) transition metal dichalcogenides materials have recently been explored as possible substrates for surface-enhanced Raman spectroscopy (SERS). However, in comparison to the conventional noble-metal-based counterpart, most of the 2D materials have very small area for SERS measurement, which is a big limitation toward practical applications. Herein, we presented our study of SERS using substrate-scale continuous ReS 2 monolayer films on flexible mica substrate. We demonstrated that the charge transfer between the target molecules and the atomically thin ReS 2 can be modulated by the underlying substrate of ReS 2 , resulting in greatly different suppressing level of FL background. Kelvin probe force microscopy revealed a large difference of surface potential between ReS 2 /SiO 2 and ReS 2 /mica, suggesting that the strong FL quenching of molecular on ReS 2 /mica might be attributed to the inert surface of layered mica. The large-area ReS 2 monolayer films on mica show a detection limit of R6G molecule around 10 −7 M and a robust SERS performance after an exposure in air for one month and repeated bending for 1000 times. Our work explores the practical application of 2D ReS 2 for molecular detection via SERS technique.
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Optical Materials Express
·
2020
·Vol. 10
·期 4
·1072-1082
·
IF 3.064
Qianhang Luo,Guowu Tang,Guowu Tang,Guowu Tang,Min Sun,Min Sun,Guoquan Qian,Zhenguo Shi,Qi Qian,Qi Qian,Qi Qian,Qi Qian,Zhongmin Yang,Zhongmin Yang,Zhongmin Yang,Zhongmin Yang
Tellurium (Te) semiconductor core optical fibers with silicate glass cladding were drawn by the molten core method. The as-drawn precursor fiber has a large core diameter of about 123 µm, which was found to be polycrystalline. What is more, a Bridgman-type fiber postprocessing technique was constructed and used for the first time to anneal the polycrystalline Te semiconductor core optical fibers. The Te core in precursor fiber was melted and recrystallized to single crystal Te with c-axis orientation parallel to fiber axis, which was confirmed by X-ray diffraction, single crystal X-ray diffraction, micro-Raman spectra, and transmission electron microscope measurement results. Enhanced conductivities were observed in single crystal Te semiconductor core optical fibers under illuminated and stress states, respectively. This work demonstrates that the Bridgman-type fiber postprocessing technique could be an effective way to fabricate single crystal semiconductor core optical fibers with large core diameters (∼ 100 µm) and long lengths (a few centimeters).
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JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2020
·
IF 2.69
Qianqian Qi,Xianwu Zeng,Licong Peng,Hailiang Zhang,Miao Zhou,Jingping Fu,Jianchao Yuan
Herein, we construct a charge - switchable polymer nano micelles poly (2-(hexamethyl eneimino) ethyl methacrylate) - b - poly (ethylene glycol) monomethyl ether methacrylate) - b - poly (diethyl enetriaminepentaacetic acid methacrylate) - b - poly (1-vinyl imidazole) - b - poly (4-vinyl phenylboronic acid) (PC7A-PEG-DTPA-VI-PBA) in different pH solutions. DOX released faster from micelles in a weakly acidic environment (pH 5.0) than at pH 7.4. In order to enhance the anti-tumor effect, the imidazole functional groups in the polymer were used to coordinate CdSeTe quantum dots (QDs) for photodynamic treatment (PDT). In addition, the surfaces of the micelles were further decorated with phenylboronic acidas a targeting group, using DTPA chelating 99mTc for SPECT imaging.It has been successfully demonstrated that the nanoparticles have a good cumulative effect on the tumor site.The structure of the polymer was characterized by 1HNMR. The morphology and particle size of the micelles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The drug loading capacity (DLC) and drug loading efficiency (DLE) of the micelles were analyzed by ultraviolet visible spectroscopy. And the pH-sensitive drug release and cytotoxicity of the micelles were verified in vitro. In vitro experiments showed that the nano micelles were noncytotoxic to different cell lines, while DOX@CdSeTe@PC7A-PEG-DTPA-VI-PBA inhibited the proliferation and promoted the apoptosis of B16F10 cells. An in vivo study with C57BL tumor-bearing mice indicated that DOX@CdSeTe@PC7A-PEG-DTPA-VI-PBA nano micelles efficiently inhibited tumor growth. Results showed that the nano micelles had good pH responsibility and biocompatibility, and the loaded DOX could be released in the weak acidic environment of tumor cells, and it was expected to be a good drug delivery system.
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JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Shuai Han,Liang Yang,Zhigang Wen,Suyun Chu,Mei Wang,Zhenyang Wang,Changlong Jiang
Residues in animal food and drinking water caused by the abuse of antibiotics lead to cell resistance and many chronic diseases in the human body. Therefore, it has become an inevitable trend to develop a fast, easy-to-use, on-site/real-time visualization method for the detection of antibiotics. Herein, we report a dual-response ratiometric fluorescence sensor which is fabricated by chelating europium ions (Eu 3+ ) onto cadmium telluride quantum dots (CdTe QDs) for real-time and visible detection of tetracycline (TC). With the TC addition, the fluorescence of probe can be seen by the naked eye, from green to yellow and finally to red, exhibiting a dosage-sensitive and broad-chromatic detection strategy for TC. The fluorescence intensity ratio of I 616 /I 512 of Eu/CdTe QDs sensor displays a good linear relation to TC concentrations in the range of 0–80 μM with a limit of detection (LOD) of 2.2 nM. In addition, the sensor can visually detect 200 nM TC in actual samples, which is lower than the maximum residue limit (MRL) of the safety standard. The methodology reported here opens a window toward the real applications of fluorescent and shows the wide applicability in pursuing the concepts simple, rapid, visual, and real-time for food safety and environmental protection.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Xia Cheng,Yuying Chai,Jian Xu,Lin Wang,Fangdi Wei,Guanhong Xu,Yong Sun,Qin Hu,Yao Cen
Inspired by the intrinsic catalytic properties of alkaline phosphatase (ALP) and tyrosinase (TYR) as well as the fluorogenic reaction between levodopa and resorcinol, a ratiometric fluorescent probe based on the CdTe/CdS/ZnS/SiO 2 QDs for visual monitoring the activity of ALP was developed. Phosphotyrosine was catalyzed into tyrosine by ALP, and then tyrosine was catalyzed into levodopa by TYR. Carboxyazamonardine, the reactive product of levodopa and resorcinol, gave rise to a strong blue fluorescence at 470 nm and quenched the red fluorescence of CdTe/CdS/ZnS/SiO 2 QDs at 620 nm due to their inner filter effect. Thus, the resulting ratiometric fluorescence acted as the signal output for quantitative ALP detection, accompanying with the fluorescence color changing from red to purple and finally blue for semiquantitative ALP detection. A good linear relationship was obtained ranging from 0.08 to 500 U L −1 with the detection limit of 0.02 U L −1 . Moreover, the probe was successfully applied to monitoring ALP activity in human serum samples without any pretreatment, and also used to screen ALP inhibitors. These results suggested that the developed method offered a highly sensitive and promising analytical platform for ALP in clinical diagnostics and paved a new way for monitoring enzymes activity visually for point-of-care diagnosis.
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Science Advances
·
2020
·Vol. 6
·期 15
·
IF 13.117
Shiyang He,Yongbo Li,Lu Liu,Ying Jiang,Jingjing Feng,Wei Zhu,Jiye Zhang,Zirui Dong,Yuan Deng,Jun Luo,Wenqing Zhang,Gang Chen
Most crystalline inorganic materials, except for metals and some layer materials, exhibit bad flexibility because of strong ionic or covalent bonds, while amorphous materials usually display poor electrical properties due to structural disorders. Here, we report the simultaneous realization of extraordinary room temperature flexibility and thermoelectric performance in Ag2Te1–xSx–based materials through amorphization. The coexistence of amorphous main phase and crystallites results in exceptional flexibility and ultralow lattice thermal conductivity. Furthermore, the flexible Ag2Te0.6S0.4 glass exhibits a degenerate semiconductor behavior with a room temperature Hall mobility of ~750 cm2 V−1 s−1 at a carrier concentration of 8.6 × 1018 cm−3, which is at least an order of magnitude higher than other amorphous materials, leading to a thermoelectric power factor also an order of magnitude higher than the best amorphous thermoelectric materials known. The in-plane prototype uni-leg thermoelectric generator made from this material demonstrates its potential for flexible thermoelectric device.
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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.
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Advanced Science
·
2020
·Vol. 7
·期 11
·1903493
·
IF 15.84
Sihui Li,Jiwu Xin,Abdul Basit,Qiang Long,Suwei Li,Qinghui Jiang,Yubo Luo,Junyou Yang
Lead-free chalcogenide SnTe has been demonstrated to be an efficient medium temperature thermoelectric (TE) material. However, high intrinsic Sn vacancies as well as high thermal conductivity devalue its performance. Here, β-Zn 4 Sb 3 is incorporated into the SnTe matrix to regulate the thermoelectric performance of SnTe. Sequential in situ reactions take place between the β-Zn 4 Sb 3 additive and SnTe matrix, and an interesting “core–shell” microstructure (Sb@ZnTe) is obtained; the composition of SnTe matrix is also tuned and thus Sn vacancies are compensated effectively. Benefitting from the synergistic effect of the in situ reactions, an ultralow κ lat ≈0.48 W m −1 K −1 at 873 K is obtained and the carrier concentrations and electrical properties are also improved successfully. Finally, a maximum ZT ≈1.32, which increases by ≈220% over the pristine SnTe, is achieved in the SnTe-1.5% β-Zn 4 Sb 3 sample at 873 K. This work provides a new strategy to regulate the TE performance of SnTe and also offers a new insight to other related thermoelectric materials.
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Nature Communications
·
2020
·Vol. 11
·期 1
·1-6
·
IF 12.121
Dong Zhuoya,Ma Yanhang
Handedness or chirality determination is a challenging and important topic in various fields including chemistry and biology, as two enantiomers have the same composition and mirror symmetry related structures, but might show totally different activities and properties in enantioselective separations, catalysis and so on. However, current methods are unable to reveal the handedness locally of a nanocrystal at the atomic-level in real-space imaging due to the well-known fact that chiral information is lost in a two-dimensional projection. Herein, we present a method for handedness determination of chiral crystals by atomic-resolution imaging using Cs-corrected scanning transmission electron microscopy. In particular, we demonstrate that enantiomorphic structures can be distinguished through chirality-dependent features in two-dimensional projections by comparing a tilt-series of high-resolution images along different zone axes. The method has been successfully applied to certify the specific enantiomorphic forms of tellurium, tantalum silicide and quartz crystals, and it has the potential to open up new possibilities for rational synthesis and characterization of chiral crystals.
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CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Hengyang Wang,Xiaofang Liu,Bin Zhang,Lisi Huang,Meiling Yang,Xiang Zhang,Hong Zhang,Guoyu Wang,Xiaoyuan Zhou,Guang Han
Binary silver chalcogenides (Ag 2 X, X = S, Se, Te) are a group of intriguing thermoelectric materials. When utilised for thermoelectrics, however, the syntheses of these chalcogenides commonly require energy-intensive, high-temperature melting-annealing processes. Herein, we have developed a general surfactant-free and scalable solution synthesis strategy to nano/micro-particles of binary silver chalcogenides, which requires neither high temperature nor long reaction duration. The chalcogenide particles were spark plasma sintered into pellets with porous structures. By modifying the Ag + /X 2− molar ratios in the solution precursors from 2:1 to 2:1.1, the thermoelectric properties of the pellets have been effectively optimised, leading to maximum ZT values of 0.84 at 380 K for Ag 2 Se, 0.59 at 650 K for Ag 2 Te and 0.27 at 540 K for Ag 2 S that are comparable to those of samples fabricated by other synthetic methods, such as melting and annealing. This study provides a general surfactant-free solution approach to binary silver chalcogenide nano/micro-materials with tuneable thermoelectric properties.
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 2
·1-9
·
IF 6.232
Xiang Ling,Zhang Feng,Feng Jian,Chen Chunyan,Cai Changqun
A method is described for the simultaneous determination of hepatocellular carcinoma-associated microRNA-122 and microRNA-199a/b-3p. This probe consists of two kinds of nanomaterials. The first comprises CdTe@CdS core-shell quantum dots which, on excitation at 375 nm give two emissions, with peak wavelengths at 543 (g-QDs) and at 627 nm (r-QDs). The second comprises gold nanoparticles acting as a quencher. In the absence of the target, g-QD-N1 and r-QD-N2 are stable due to the fluorescence stability. With the addition of microRNA-122 and microRNA-199a/b-3p, g-QD-N1 and r-QD-N2 are conjugated to the surface of AuNP-S1/S2 through base complementary pairing. As a result, fluorescence resonance energy transfer (FRET) occurs, resulting in a decrease at 550 nm and 635 nm respectively, which can realize the simultaneous detection of two different microRNAs. Detection is achieved within 50 min. The detection limits (3σ/k) are 0.2 nM for microRNA-122 and 0.5 nM for microRNA-199a/b-3p. The clinical applicability of the assay was demonstrated by detecting microRNAs in human serum and different cell lysates.
Schematic for the simultaneous determination of microRNA-122 and microRNA-199a/b-3p by FRET.
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