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91.
Anthony Jolly Dandan Miao Maxime Daigle Prof. Dr. Jean-François Morin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4652-4661
The solution-phase synthesis is one of the most promising strategies for the preparation of well-defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect-free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd- and Ni-catalyzed reactions. 相似文献
92.
Dr. Qing Li Shenhua Li Dr. Shasha He Wan Chen Penghui Cheng Dr. Yan Zhang Prof. Qingqing Miao Prof. Kanyi Pu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7084-7089
Discriminative detection of invasive and noninvasive breast cancers is crucial for their effective treatment and prognosis. However, activatable probes able to do so in vivo are rare. Herein, we report an activatable polymeric reporter (P-Dex) that specifically turns on near-infrared (NIR) fluorescent and photoacoustic (PA) signals in response to the urokinase-type plasminogen activator (uPA) overexpressed in invasive breast cancer. P-Dex has a renal-clearable dextran backbone that is linked with a NIR dye caged with an uPA-cleavable peptide substrate. Such a molecular design allows P-Dex to passively target tumors, activate NIR fluorescence and PA signals to effectively distinguish invasive MDA-MB-231 breast cancer from noninvasive MCF-7 breast cancer, and ultimately undergo renal clearance to minimize the toxicity potential. Thus, this polymeric reporter holds great promise for the early detection of malignant breast cancer. 相似文献
93.
Borate is considered one of the most important additives for improving the fire-resistance of combustible polymers because of its smoke suppression, low toxicity, and good thermal stability. However, the size of prepared borate is usually in the micrometer range, which makes it difficult to disperse in a polymer matrix, thus hindering its use as fire-retardant material. The preparation and application of borate nanomaterial as flame retardant is considered an effective method. However, the preparation of barium borate nanomaterials as flame retardant has not been reported. In this paper, nanosheets and nanoribbons with different sizes for a new barium borate BaO·4B2O3·5H2O are prepared by hydrothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), thermogravimetric analysis-differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The flame-retardant properties of polypropylene (PP)/BaO·4B2O3·5H2O composites are investigated by thermogravimetric analysis (TG), differential scanning calorimetry (DSC) thermal analysis methods and limited oxygen index (LOI) method. Considering the near TG mass losses and the near LOI values for PP with 10% prepared BaO·4B2O3·5H2O nanosheet and nanoribbon, their flame-retardant properties need to be further evaluated by non-isothermal decomposition kinetic method. The apparent activation energy for this decomposition reaction was obtained from the slope by plotting ln(β/Tp2) against 1/Tp according to Kissinger's model. With the reduction of TG mass loss, increased heat absorption in DSC under N2 atmosphere, increased apparent activation energy Ea for the thermal decomposition of PP/BaO·4B2O3·5H2O composite as well as increased LOI value, the flame-retardant performance of prepared BaO·4B2O3·5H2O samples with PP gradually improved from bulk to nanoribbon to nanosheet. This can be attributed to the decrease in the size of BaO·4B2O3·5H2O samples because the smaller sample size leads to improved dispersion and increased contact area with the polymer. The flame-retardant mechanism is discussed by analyzing the after-flame chars of the PP/BaO·4B2O3·5H2O composite in SEM images, which show that the char layer is more compact and continuous for the PP/BaO·4B2O3·5H2O nanosheet composite. The influence of loading BaO·4B2O3·5H2O nanomaterials on the mechanical properties of PP is also tested using a universal material testing machine, in which the PP/BaO·4B2O3·5H2O nanosheet composite has higher tensile strength. The PP/BaO·4B2O3·5H2O nanosheet composite has the best flame-retardant and mechanical properties, which is promising to be developed for the application as flame-retardant material. 相似文献
94.
Anthony Jolly Dandan Miao Maxime Daigle Jean‐Franois Morin 《Angewandte Chemie (International ed. in English)》2020,59(12):4624-4633
The solution‐phase synthesis is one of the most promising strategies for the preparation of well‐defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect‐free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd‐ and Ni‐catalyzed reactions. 相似文献
95.
Yan‐mei Shi Lin Mei Jun‐xia Zhang Kai Hu Xi Zhang Zhu‐zhu Li Ming‐san Miao Xiu‐min Li 《Electroanalysis》2020,32(7):1507-1515
A new electrochemical sensor material has been fabricated via the non‐covalent functionalization of reduced graphene oxide (rGO) and soluble tetramino zincphthalocyanines (ZnPc‐NH2). Immobilization of uricase onto the synthesized nanohybrids can evidently improve the electrocatalytic activity and selectivity. The obtained composite membrane possesses a great enhancement of electron transfer rate and excellent synergistic electrocatalytic effect toward uric acid (UA) oxidation under the working potential at 0.620 V vs. Ag/AgCl with a scan rate of 0.125 V/s. The effects of the experimental parameters on the electrochemical oxidation responses of UA were investigated and optimized in detail. Under the optimized conditions, the peak currents were proportional to the UA concentration in a range from 0.5 to 100 μmol/L with detection limit of 0.15 μmol/L. Moreover, the developed sensor was applied for UA determination in human urine samples with high accuracy and satisfactory recovery, which is envisioned to have promising applications in monitoring UA in clinical research. 相似文献
96.
Xinsheng Liu Lei Zhao Bin Miao Zhiqi Gu Jin Wang Huoxiang Peng Jiande Li Wei Sun Jiadong Li 《Electroanalysis》2020,32(2):422-428
Biosensors based on field‐effect transistor (FET) structures have attracted considerable attention because they offer rapid, inexpensive parallel sensing and ultrasensitive label‐free detection. However, long‐term repeatable detection cannot be performed, and Ag/AgCl reference electrode design is complicated, which has hindered FET biosensors from becoming truly wearable health‐monitoring platforms. In this paper, we propose a novel wearable detection platform based on AlGaN/GaN high‐electron‐mobility transistors (HEMTs). In this platform, a sweatband was used to continuously collect sweat, and a pH detecting unit and a potassium ion detecting unit were formed by modifying different sensitive films to realize the long‐term stable and repeatable detection of pH and potassium ions. Experimental data show that the wearable detection platform based on AlGaN/GaN HEMTs has good sensitivity (pH 3–7 sensitivity is 45.72 μA/pH; pH 7.4–9 sensitivity is 51.073 μA/pH; and K+ sensitivity is 4.94 μA/lgαK+), stability (28 days) and repeatability (the relative standard deviation (RSD) of pH 3–7 sensitivity is 2.6 %, the RSD of pH 7.4–9 sensitivity is 2.1 %, and the RSD of K+ sensitivity is 7.3 %). Our newly proposed wearable platform has excellent potential for predictive analytics and personalized medical treatment. 相似文献
97.
Wencan Jiang Gongwei Sun Wenbin Cui Shasha Men Miao Jing Danna Pu Sichun Zhang Xiaozhou Yuan Xinrong Zhang Chengbin Wang 《Molecules (Basel, Switzerland)》2020,25(22)
Background: Element-tagged immunoassay coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection has the potential to revolutionize immunoassay analysis for multiplex detection. However, a further study referring to the standard evaluation and clinical sample verification is needed to ensure its reliability for simultaneous analysis in clinical laboratories. Methods: Carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) were chosen for the duplex immunoassay. The performance of the assay was evaluated according to guidelines from the Clinical and Laboratory Standards Institute (CLSI). Moreover, reference intervals (RIs) of CEA and AFP were established. At last, 329 clinical samples were analyzed by the proposed method and results were compared with those obtained with electrochemiluminescent immunoassay (ECLIA) method. Results: The measurement range of the assay was 2–940 ng/mL for CEA and 1.5–1000 ng/mL for AFP, with a detection limit of 0.94 ng/mL and 0.34 ng/mL, respectively. The inter-assay and intra-assay imprecision were all less than 6.58% and 10.62%, respectively. The RI of CEA and AFP was 0–3.84 ng/mL and 0–9.94 ng/mL, respectively. Regarding to clinical sample detection, no significant difference was observed between the proposed duplex assay and the ECLIA method. Conclusions: The ICP-MS-based duplex immunoassay was successfully developed and the analytical performance fully proved clinical applicability. Well, this could be different with other analytes. 相似文献
98.
CuCl2掺杂聚苯胺催化合成苯甲醛1,2-丙二醇缩醛 总被引:3,自引:0,他引:3
缩醛是一类重要化合物,具有原料来源丰富、生产工艺简单、化学性质稳定等优点,近20年来作为新型香料在日用香精和食品香精中均有广泛应用[1-2]。根据酸催化机理,Lewis酸可增强羰基碳的正电性,有利亲核试剂的进攻。研究表明,不少无机盐都是这类反应的高效、高选择性的催化剂,又因为无机盐价廉、易得等优点,所以用其作为催化剂具有更加重要的实际意义。聚苯胺(PAn)以其独特的掺杂现象及良好的稳定性为催化载体的选择提供了新的途径[3-4]。若以PAn为载体,将具有催化活性的路易斯酸掺杂其中,可降低路易斯酸的流失量,并克服其易潮解、腐蚀设备… 相似文献
99.
在酸氧化后的多壁碳纳米管上化学还原镀钯,用水将镀钯后的碳管清洗至中性并配制成悬浊液,将悬浊液旋涂在真空溅射的叉指金电极表面,干燥后作为气敏膜,把气敏膜暴露于一定浓度的苯气体中,检测传感器的电流变化,并计算其灵敏度。镀钯后的多壁碳管在室温下对苯响应和回复迅速,电导变化与苯气体的浓度呈良好的线性关系,其线性回归方程y=0.0041x 0.1288,r=0.9546。Pd颗粒对苯分子和碳管壁结构缺陷间的电子转移的促进作用可能是多壁碳管镀钯后产生良好气敏响应的原因。 相似文献
100.
Paracyclophene based monomers can be polymerized in a living fashion using the alkylidene initiator Mo(NAr)(CHCMe2Ph)(OCMe(CF3)2)2. The cis-specific nature of the polymerization is critical, since small amounts of trans olefin in the backbone renders the material insoluble. These polymers have complex photophysical behavior, probably a consequence of the close proximity of chromophores along the polymer backbone. Polymerization of 9-(tert-butyldimethylsilyloxy)-[2.2]-paracyclophan-1-ene produces a new precursor material which furnishes PPV under remarkably mild conditions. 相似文献