MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-10
·
IF 5.479
Qin Dan,Wang Jiangtao,Ge Changzi,Lian Ziru
A straightforward method has been developed for selective separation of chloramphenicol (CAP) from marine sediment samples. Magnetic molecularly imprinted nanoparticles (NPs) of type Fe 3 O 4 @SiO 2 were prepared via surface imprinting with CAP. The NPs were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and thermogravimetric analysis. They have perfect core-shell structure, excellent thermal stability, high affinity and selectivity to CAP. The imprinting factor and Scatchard analysis also reveal good specific recognition to the template. The imprinted NPs were applied as sorbents for fast and selective extraction of CAP from marine sediment samples. The experimental parameters affecting separation efficiency were optimized. Three marine sediment samples were analyzed. Following desorption with methanol/water (90/10, v /v), CAP was quantified by HPLC with DAD detection. The limit of detection is 0.1 μg L −1 with a good linear response between 0.1–20 mg L −1 of CAP concentration (R 2 = 0.999, n = 3). The method exhibits satisfactory recoveries from spiked samples (77.9–102.5%) and has low relative standard deviations (<6.3%). The magnetic material can be used at least 5 times by the regeneration without any loss of selectivity and adsorption capability.
Schematic presentation of magnetic molecularly imprinted nanoparticles (MMIPs) as sorbent for fast extraction and chromatographic analysis of chloramphenicol (CAP) from marine sediments. CAP-MMIPs are synthesized by surface imprinting method using 3-methacryloxy propyl trimethoxy silane (MPS) as the silane coupling agent.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-9
·
IF 5.479
Sun Jiangjiang,Wang Qin,Yang Jiajun,Zhang Jianjian,Li Zheng,Li Hua,Yang Xiao-Feng
The authors describe a carbon dot-based fluorescent probe for biothiols. Green emissive carbon dots (g-CDs; with λ ex /λ em maxima of 407/505 nm) were synthesized by a one-step solvothermal method starting from 3-diethylaminophenol. They were then covalently functionalized with 2,4-dinitrobenzenesulfonyl chloride to afford 2,4-Dinitrobenzenesulfonate-functionalized CDs (g-CD-DNBS) as a nanoprobe for biothiols. The fluorescence of the g-CD-DNBS is quite weak. Upon addition of biothiols, the DNBS group of the probe is removed by thiol groups. This results in gradual restoration of the green fluorescence. The nanoprobe exhibits high selectivity for biothiols over other amino acids and biological molecules. The detection limits for cysteine, homocysteine and glutathione are 69, 74 and 69 nM (S/ N = 3), respectively. The probe was applied to image biothiols in SMMC-7721 cells.
Schematic presentation of the mechanism of 2,4-dinitrobenzenesulfonate-functionalized carbon dots (g-CD-DNBS) for the detection of biothiols. g-CDs: green emissive carbon dots.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-7
·
IF 5.479
Zhao Maoyu,Qi Wenjing,Fu Yuling,He Hongkun,Wu Di,Qi Lin,Li Rong
A method is presented for electrochemiluminescent (ECL) detection of the food additive curcumin via an energy transfer strategy and by using luminol-doped silica nanoparticles (luminol-NPs). The ECL emission of the luminol-NPs (peaking at 425 nm) is reduced in the presence of curcumin due to spectral overlap. The assay can be performed within 1 min, response is linear in the 0.1 to 100 µM curcumin concentration range, and the limit of detection is 32 nM. The method is selective over many ions, adenosine triphosphate, ascorbic acid, cysteine and folic acid. It was successfully applied to the determination of curcumin in spiked human serum and urine. The average recoveries range from 99.0 to 102.6%.
Electrochemiluminescence (ECL) “turn-off” detection of curcumin at levels as low as 32 nM via energy transfer using luminol-doped silica nanoparticles. No hydrogen peroxide (H 2 O 2 ) is used in ECL detection which makes the luminol-NPs ECL system more stable than the conventional luminol-H 2 O 2 ECL system.
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AMB Express
·
2019
·Vol. 9
·期 1
·1-9
·
IF 2.226
Zhao Shuxue,Hu Chunhui,Guo Lizhong,Li Kuiran,Yu Hao
A 3-hydroxypyridine degrading bacterium, designated strain DW-1, was isolated from petroleum contaminated soil in Liao River China. 16S rRNA-based phylogenetic analysis indicates that strain DW-1 belongs to genus Agrobacterium. The optimal cultivation temperature and pH for strain DW-1 with 3-hydroxypyridine were 30 °C and 8.0, respectively. Under optimal conditions, strain DW-1 could completely degrade up to 1500 mg/L of 3-hydroxypyridine in 66 h. The 3-hydroxypyridine degradation pathway of strain DW-1 was suggested by HPLC and LC–MS analysis. The first reaction of 3-hydroxypyridine degradation in strain DW-1 was α-hydroxylation so that the major metabolite 2,5-dihydroxypyridine was produced, and then 2,5-dihydroxypyridine was transformed by a Fe2+-dependent dioxygenase to form N-formylmaleamic acid. N-Formylmaleamic acid will be transformed to maleic acid and fumaric acid through maleamic acid. This is the first report of the 3-hydroxypyridine degradation pathway and the utilization of 3-hydroxypyridine by a Agrobacterium sp. It may be potentially used for the bioremediation of environments polluted with 3-hydroxypyridine.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-8
·
IF 5.479
Wang Jing,Li Bingzhi,Lu Qiaoyun,Li Xiaoyun,Weng Chenyuan,Yan Xiaoqiang,Hong Junli,Zhou Xuemin
The authors describe a versatile aptasensing scheme based on the use of polypyrrole nanoparticles (PPyNPs) and DNA-silver nanoclusters (DNA-AgNCs) for multiple target detection. The DNA-AgNCs consist of two functional domains, viz. (a) a nucleation domain for attaching the metal core of the nanoclusters, and (b) a recognition domain which consists of a single-stranded aptamer. In the absence of analytes, the single-strand recognition domain will be absorbed onto the surface of the PPyNPs through π stacking and hydrophobic interactions. As a result, the red fluorescence of the DNA-AgNCs (with excitation/emission peaks at 535/625 nm) is quenched by the PPyNPs. On introducing the analytes, the DNA-AgNCs will bind them. This leads to the desorption of DNA-AgNCs and the recovery of the red fluorescence. Based on the above strategy, a versatile, sensitive and selective aptasensor was established for detection of adenosine, thrombin and interferon-gamma. The method was applied to the detection of the above targets in (spiked) serum samples and gave satisfactory results, with detection limit of 0.58 nM for IFN-γ, 0.39 nM for adenosine, and 2.2 nM for thrombin. The use of PPyNPs results in uniquely low non-specific absorption and in improved analytical results in case of real-sample analysis when compared to previously reported methods.
Schematic illustration of DNA-silver nanoclusters and polypyrrole nanoparticles in an aptasensor for detection of multiple targets.
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ACTA PHARMACOLOGICA SINICA
·
2019
·Vol. 40
·期 10
·1334-1342
·
IF 4.01
Lu Bin,Chen Xiao-bing,Hong Yu-cai,Zhu Hong,He Qiao-jun,Yang Bo,Ying Mei-dan,Cao Ji
Ferroptosis is a newly characterized iron-dependent form of nonapoptotic regulated cell death triggered by lipid reactive oxygen species (LOOH). The dysregulation of ferroptosis is highly related to cancer, and the induction of ferroptosis is also proposed as a potential strategy for cancer therapy. Although several key regulators have been identified that are involved in ferroptosis, the molecular mechanism underlying this process remains largely unknown. Here, we report that Peroxiredoxin-6 (PRDX6) is a bona fide negative regulator of ferroptotic cell death. The knockdown of intracellular PRDX6 significantly enhances LOOH and ferroptotic cell death triggered by ferroptosis inducers (Erastin and RSL-3), which is correlated with the transcriptional activation of heme oxygenase-1. Moreover, overexpression of heme oxygenase-1 enhances both Erastin- and RSL-3-triggered LOOH, suggesting that heme oxygenase-1 mediates PRDX6 silencing-enhanced ferroptosis. More importantly, the application of a specific PRDX6 phospholipase A2 (iPLA2) inhibitor, MJ-33, synergistically enhances the ferroptosis induced by Erastin, suggesting that PRDX6 removes LOOH through its iPLA2 activity. Thus, our findings reveal an essential role of PRDX6 in protecting cells against ferroptosis and provide a potential target to improve the antitumor activity of ferroptosis-based chemotherapy.
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Biotechnology for Biofuels
·
2019
·Vol. 12
·期 1
·1-15
·
IF 5.452
Fang Wei,Xue Saisai,Deng Pengjun,Zhang Xuecheng,Wang Xiaotang,Xiao Yazhong,Fang Zemin
Background Starch is an inexpensive and renewable raw material for numerous industrial applications. However, most starch-based products are not cost-efficient due to high-energy input needed in traditional enzymatic starch conversion processes. Therefore, α-amylase with high efficiency to directly hydrolyze high concentration raw starches at a relatively lower temperature will have a profound impact on the efficient application of starch. Results A novel raw starch digesting α-amylase (named AmyZ1) was screened and cloned from a deep-sea bacterium Pontibacillus sp. ZY. Phylogenetic analysis showed that AmyZ1 was a member of subfamily 5 of glycoside hydrolase family 13. When expressed in Escherichia coli , the recombinant AmyZ1 showed high activity at pH 6.0–7.5 and 25–50 °C. Its optimal pH and temperature were 7.0 and 35 °C, respectively. Similar to most α-amylases, AmyZ1 activity was enhanced (2.4-fold) by 1.0 mM Ca 2+ . Its half-life time at 35 °C was also extended from about 10 min to 100 min. In comparison, AmyZ1 showed a broad substrate specificity toward raw starches, including those derived from rice, corn, and wheat. The specific activity of AmyZ1 towards raw rice starch was 12,621 ± 196 U/mg, much higher than other reported raw starch hydrolases. When used in raw starch hydrolyzing process, AmyZ1 hydrolyzed 52%, 47% and 38% of 30% (w/v) rice, corn, and wheat starch after 4 h incubation. It can also hydrolyze marine raw starch derived from Chlorella pyrenoidosa , resulting in 50.9 mg/g DW (dry weight of the biomass) of reducing sugars after 4 h incubation at 35 °C. Furthermore, when hydrolyzing raw corn starch using the combination of AmyZ1 and commercial glucoamylase, the hydrolysis rate reached 75% after 4.5 h reaction, notably higher than that obtained in existing starch-processing industries. Conclusions As a novel raw starch-digesting α-amylase with high specific activity, AmyZ1 efficiently hydrolyzed raw starches derived from both terrestrial and marine environments at near ambient temperature, suggesting its application potential in starch-based industrial processes.
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CHEMICAL PAPERS
·
2019
·Vol. 74
·期 2
·485-497
·
IF 1.246
Quan Cong,Liu Jiayu,Sun Wei,Cheng Xinjian
It is extremely necessary to detect heavy metals sensitively and selectively, especially the ions that will cause great harm to humans and the environment. This work deals with two fluorescent chemosensors and their outstanding role when detecting Zn 2+ and Cd 2+ ions. First, a small molecular chemosensor (TPB) has been designed and synthesized via Suzuki reaction using one part of benzene-1,3,5-triyltriboronic acid and three parts of 2-bromo-1, 10-phenanthroline as starting materials. And then, its corresponding macromolecular fluorescent chemosensor (PTPB) was synthesized. The infrared spectra, mass spectrometry (MS), and 1 H-NMR were used to study the structures of TPB and PTPB. From what has been studied, the TPB and PTPB were stable in a relative wide pH range. As soon as the Cd 2+ and Zn 2+ ions added, fluorescence of the two sensors TPB and PTPB was changed obviously. In addition, PTPB was found have better performance to both Cd 2+ and Zn 2+ than TPB through the ‘‘molecular wire’’ mechanism. Job’s plots were also be tested, showing that the combination ratio of TPB and PTPB to Cd 2+ and Zn 2+ were both 3:1 (ion/sensor). In addition, the minimum detection limits of the macromolecular chemosensor PTPB for Cd 2+ and Zn 2+ reached 0.424 μM and 1.27 μM, respectively.
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JOURNAL OF NANOPARTICLE RESEARCH
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2019
·Vol. 21
·期 7
·1-9
·
IF 2.009
Zhang Aiqin,Xiao Yuanhua,Das Paramita,Zhang Linsen,Zhang Yong,Fang Hua,Wang Lixia,Cao Yang
Silver nanoparticles (AgNPs), especially with small size, are easy to release silver ion in aqueous solution owing to various reasons, which would significantly affect the stability, properties, and application of AgNPs. In this paper, monodisperse AgNPs with small size of ca. 10 nm were successfully prepared based on solid-state reactions. Ascorbic acid (AA) was used as reductant and tannic acid (TA) was used both as reductant and stabilizer in this environmentally friendly reaction. The dissolution and regeneration of the as-prepared TA-AgNPs in pure water were investigated by UV−vis spectra, TEM observations, and differential pulse anodic stripping voltammetry. The results indicated that the TA-AgNPs showed a little higher dissolution than conventional PVP-coated ones with similar size. However, the dissolved silver ion in the TA-AgNPs aqueous solution could be recovered just by adjusting the pH of the solution, which could be attributed to the reductant performance of TA at alkaline conditions. After regeneration, some smaller nanoparticles appeared in TA-AgNPs aqueous solution, indicating that new nucleation formed and the dissolved silver ions were actually recovered to Ag 0 .
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2019
·Vol. 321
·期 1
·235-242
·
IF 1.186
Zu Jianhua,Fu Lingxiao,Tang Fangdong,He Linfeng
A new pyridyl anion exchange resin (PS-N) was synthesized by chloroacetylation and quaternization on the polystyrene-divinylbenzene microspheres (PS) and was characterized by FT-IR, TGA, and X-ray photoelectron spectroscopy. PS-N was applied to study the removal of Re(VII), a chemical analogue of 99 Tc, to investigate the effect of solution acidity, resin dose and contact time on the adsorption efficiency. The adsorption process corresponded with the Langmuir isotherm model and matches well with pseudo-second-order kinetics. Based on the adsorption results of Re(VII), the adsorption efficiency of 99 Tc was examined to be 99.5% at optimum conditions.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 8
·1-10
·
IF 5.479
Zhu Yanyan,Zhang Xuan,Sun Jiameng,Li Meng,Lin Yulong,Kang Kai,Meng Yang,Feng Zhongliang,Wang Jing
Ultrafine platinum nanoparticles are grown on a 3D graphene framework (GF–Pt) via a hydrothermal method. The material, when placed on a glassy carbon electrode (GCE), displays enhanced electrocatalytic activity towards glucose oxidation. This is assumed to be the result of the numerous easily accessible active sites, an enlarged electrochemically active area, and the presence of multiple electron/ion transport channels. The modified GCE can be operated at a low potential (− 0.15 V vs. Ag/AgCl) has linear responses in the 0.1 μM − 0.01 mM and 0.01 mM – 20 mM glucose concentration range, and a 30 nM detection limit. It was applied to the rapid determination of glucose in human serum samples.
Schematic presentation of a glassy carbon electrode modified with ultrafine Pt nanoparticles grown on a graphene framework (GFs–Pt). GFs–Pt presents enhanced electrocatalytic activity towards glucose oxidation. GFs–Pt is used in a sensitive non-enzymatic amperometric glucose sensor.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 24
·25107-25116
·
IF 2.914
Liu Guanghua,Lin Guanquan,Lin Xida,Zhou Hongjun,Chen Huayao,Hao Li,Zhou Xinhua
The overdosage use of pesticide was harmful to the environment and human health, which was mainly caused by the low utilization rate of the pesticide. However, the pesticide microcapsule with sustained-release and stimulating response properties could effectively solve this problem. Preparation of carboxymethyl cellulose grafting dimethyldiallylammonium chloride (CMC-g-PDMDAAC) through grafting polymerization and trapping as well as encapsulation of avermectin (AVM) via electrostatic interactions resulted in the formation of AVM/CMC-g-PDMDAAC microcapsules. The results showed that the particle size was 200~300 nm. The encapsulation efficiency was as high as 72.06%. Furthermore, the remaining rate of encapsulated AVM increased from 50.0 to 81.60% after UV irradiation for 359 min. The microcapsules exhibited significant enzyme and pH stimuli responsiveness. Finally, CMC-g-PDMDAAC had no significant difference effect on the toxicity of AVM, AVM could be found, and DMDAAC featured a synergistic effect on the toxicological effects of AVM.
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危险品化学品经营许可证（带存储）