MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-8
·
IF 5.479
Chen Donghua,Wen Siming,Peng Rulin,Gong Qingsong,Fei Junjie,Fu Zhuo,Weng Chao,Liu Minna
Mesoporous silica nanospheres (MSNs) are used in a triple signal amplification chemiluminescent (CL) assay for microRNA-21. It is based on (a) the synergistic amplification via loading and controlled-release of signal reagents by MSNs, (b) target recycling amplification, and (c) the enhancement effect of graphene oxide quantum dots (GOQD). CL is generated by the bis(2,4,6-trichlorophenyl) oxalate (TCPO) and H 2 O 2 reaction in the presence of the fluorophore rhodamine B (RB). RB is firstly loaded into the pores of MSNs modified with amino groupsand coupled with ssDNA. Then, the pores are capped by GOQD. Upon the addition of microRNA-21 into the system, the designed ssDNA assumes a double stranded structure. With the aid of duplex-specific nuclease, the double strand structure is cleaved and the free microRNA-21 enters into the next cycling process to combine with other ssDNA forming double strand structures. After several cycling process, amounts of GOQDs departing from the surface of MSNs cause the opening of the pores of MSNs and the release of RB causes the CL of TCPO-H 2 O 2 reaction system. Free GOQDs can lead to a further CL enhancement. By this method, even a low amount of microRNA-21 leads to a large number of released RB molecules and triggers high-intensity CL. The method was applied in an assay where the CL signal increases linearly with the logarithm of the microRNA-21 concentration in the range of 0.005–50 pmol L −1 and the detection limit is 1.7 fmol L −1 (at 3σ).
Schematic presentation of a triple signal amplification chemiluminescence (CL) analysis platform based on rodamine B (RB) loading and controlled release, target recycling amplification and graphene oxide quantum dots (GOQD) as the enhancer for analysis of microRNA-21 in human serum.
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JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2019
·Vol. 34
·期 3
·752-759
·
IF 0.605
Tang Qiuhan,Zhao Rui,Lu Qi,Qing Guangyan
A novel phosphoprotein separation material was developed, which is constructed by a magnetic mesoporous Fe 3 O 4 @TiO 2 (Fe 3 O 4 @mTiO 2 ) microsphere and a 5-aminoisophthalic acid (AIPA) monolayer that provides additional binding sites toward phosphate groups. The results of characteristic experiments demonstrated that Fe 3 O 4 @mTiO 2 -AIPA had good dispersability, high magnetic susceptibility, and satisfactory grafting ratio of AIPA, ascribed to the large specific surface area of the inorganic substrate. Taking advantages of these features, Fe 3 O 4 @mTiO 2 -AIPA was successfully utilized to separate α -casein (a typical phosphoprotein) and bovine serum albumin (BSA, a typical non-phosphoprotein) from their mixtures (molar ratio = 1:2). Through adjusting pH and polarity of solutions, the BSA and α -casein were respectively enriched in washing fraction and elution fraction. This result displays the good potential of Fe 3 O 4 @mTiO 2 -AIPA for application in phosphoprotein enrichment.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 12
·11336-11345
·
IF 2.195
Wu Shuangshuang,Yin Jinchang,Qu Hongbin,Li Anming,Liu Lizhi,Shao Yuanzhi
Lanthanide fluorescence nanoprobe is versatile in multicolor cell imaging, although it still faces a great challenge in improving its luminescent efficiency. Herein, we validated the feasibility of lanthanide ions co-doped gadolinium phosphate nanocrystals serving as a safe, effective and color-tunable fluorescence probe for live cell imaging. Well-crystallized hexagonal phase GdPO 4 nanoparticles with multi-morphologies such as nanowires, nanorods, tetragonal nanocubes and hexagonal nanoprisms were synthesized via a typical hydrothermal method. We have systematically investigated the synthesis of different morphologies of GdPO 4 nanoparticles through adjusting their processing parameters. The nanoparticles can gain a bright color-tunable photoluminescence from red, orange, yellow to green region when the GdPO 4 nanoparticles are co-doped with Eu 3+ and Tb 3+ ions. The Tb 3+ doping significantly enhances the characteristic 4f → 4f transitions of Eu 3+ owing to a specific cross-relaxation process from Tb 3+ to Eu 3+ ions; the mechanism underlying the cross relaxation was exposited in detail. Further biological experiments in vitro proved that the prepared nanoprisms could exhibit a favourable biocompatibility with negligible toxicity. The current investigation manifests a high potential of the nanoparticles applicable to fluorescence imaging probe for live cells.
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JOURNAL OF NANOBIOTECHNOLOGY
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2019
·Vol. 17
·期 1
·1-14
·
IF 5.345
Gasmalla Hind Baballa,Lu Xiaoquan,Shinger Mahgoub Ibrahim,Ni Lubin,Chishti Aadil Nabi,Diao Guowang
Background Iron oxide nanocomposites have received a great attention for their application in various fields like physics, medicine, biology, and material science etc., due to their unique properties, such as magnetism, electrical properties, small size, biocompatibility and low toxicity. Methods Fe 3 O 4 /Ag 3 PO 4 @WO 3 nanocomposites with different weight percent of Ag 3 PO 4 were successfully prepared through fabricated Ag 3 PO 4 /Fe 3 O 4 with WO 3 via in situ fabrication method, electrospinning involved precursor solution preparation and spinning to enhance photocatalyst performance under simulated sunlight for the degradation of methylene blue (MB) and antibacterial activity against Staphylococcus aureus ( S. aureus ). Results The photocatalytic degradation of methylene blue (MB) under simulated light irradiation indicated that the nanocomposite with 0.25 mg of Ag 3 PO 4 has the best activity. An additional advantage of these photocatalysts is magnetic recoverability, using external magnetic field and photocatalytic stability of the nanocomposites was evaluated for three cycles. In addition, using different scavengers, holes (h + ) and superoxide radical (O
·−) 2
radicals and hydroxide radical ( · OH) were identified the main oxidative species in the degradation reaction of methylene blue. Conclusions The results reveal that Fe 3 O 4 /Ag 3 PO 4 @WO 3 -0.25 nanocomposites have photocatalytic and antibacterial activity against S. aureus. The photocatalyst and mechanism based on the enhancement of electron transfer processes between Ag 3 PO 4 and WO 3 nanoparticles.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 5
·1-9
·
IF 5.479
Li Guiyin,Zeng Junxiang,Liu Huiling,Ding Ping,Liang Jintao,Nie Xinmin,Zhou Zhide
Alpha-fetoprotein (AFP) is a reliable clinical marker of hepatocellular carcinoma (HCC). A highly sensitive fluorometric aptamer nanoprobe is described for AFP detection. It is based on fluorescence resonance energy transfer (FRET) between AFP aptamer labelled with 5-carboxyfluorescein (FAM) and palladium nanoparticles (PdNPs). The PdNPs quench the green fluorescence of the FAM-AFP aptamer via interactions between nitrogen functional groups of the AFP aptamer and PdNPs. When AFP was introduced into the FAM-AFP aptamer-PdNPs FRET system, the AFP aptamer preferentially combines with AFP. This results in a conformational change and weakens the interaction between the aptamer and the PdNPs. Thus, the fluorescence of FAM recovers. The fluorescence recovery of FAM increases linearly in the 5.0–150 ng·mL −1 AFP concentration range and has a 1.4 ng·mL −1 detection limit. The assay was applied to the analysis of spiked diluted human serum. The recovery values ranged from 98.3 to 112.9%, with relative standard deviations of <1.1%. This biosensing strategy provides a reliable and ultrasensitive protocol for the quantification of biomarkers with relevant antigens and aptamers.
Schematic presentation of a fluorometric aptamer nanoprobe for AFP assay based on fluorescence resonance energy transfer (FRET) between AFP aptamer labelled with 5-carboxyfluorescein (FAM) and palladium nanoparticles (PdNPs).
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 11
·10651-10659
·
IF 2.195
Huang Xuechen,Liu Bang,Wang Shuanghu,Liu Yuxi,Wu Gang
Bi 2 O 3 - and MgO-doped BaTiO 3 –(Na 1/4 Bi 3/4 )(Mg 1/4 Ti 3/4 )O 3 (BT–NBMT) ceramics were synthesized from a solid-state approach, and then the impacts of Bi 2 O 3 and MgO dosages on the structures and dielectric characteristics were studied. Obvious dual peaks were observed with Bi 2 O 3 dosage to 0.04 and MgO dosage to 0.02. The low-temperature dielectric stability and grain size of the Bi 2 O 3 dopant were improved, while those of the MgO dopant hardly changed with MgO dosage to 0.02, indicating the core/shell microstructure of BT–NBMT was formed following the dissolving-precipitating mechanism of BT systems doped with low-melting-point substances. The low-temperature dielectric stability of the Bi 2 O 3 - or MgO-doped BT–NBMT ceramics first improved and then deteriorated with the increase of doping concentrations. High-temperature stability and diffuse-state transition were found in the optimal ceramics. The second phases of Bi 2 O 3 and MgO, magnesium titanium compounds were observed in Bi 2 O 3 and MgO dopants, respectively. Bi 2 O 3 -doped and MgO-doped ceramics exhibited a fine-grained microstructure and significant grain growth, respectively, and the core/shell microstructure was responsible for the dielectric temperature stability for Bi 2 O 3 dopants and collapsed to a homogeneous one with remarkable grain growth and the second phases for MgO dopants.
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FIBERS AND POLYMERS
·
2019
·Vol. 20
·期 3
·538-544
·
IF 1.439
Li Shanshan,Ding Fang,Lin Xinghuan,Li Zhiguang,Ren Xuehong
In this study, a novel organic-inorganic hybrid intumescent flame-retardant composed of nanosilica (SiO 2 ) covered with polyethyleneimine (PEI) and phytic acid (PA) was coated on cotton fabrics by layer-by-layer (LbL) self-assembly to improve flame retardancy of cotton fabrics. FT-IR, SEM and EDX were used to characterize the deposition of SiO 2 -PEI/PA on the surface of cotton fabrics. The LbL assembly process had a minor effect on the tensile strength of cotton fabrics. With the synergistic effect of phosphorus, nitrogen and silicon, the coated cotton fabrics with only 7 bilayers exhibited excellent flame retardancy with an LOI value of 33.7 % and a char length of 7.5 cm. TG analysis results showed that cotton/(SiO 2 -PEI/PA) 7 had 40.7 % char residue at 600 °C, compared with 8 % char residue of uncoated cotton fabrics. Cone calorimetry test confirmed that cotton/(SiO 2 -PEI/PA) 7 displayed a major reduction in peak of heat release rate (pHRR) of 75 % and total heat release (THR) of 52 %.
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Scientific Reports
·
2019
·Vol. 9
·期 1
·1-5
·
IF 4.011
Mei Jianfeng,Chen Xiang,Liu Jianghua,Yi Yu,Zhang Yanlu,Ying Guoqing
Genistein is known to have multiple biological activities and has great potential for use as a preventative medicine and in disease treatment. Genistein can be extracted from plants, but also can be obtained from its glycoside form, sophoricoside, which is more abundant in some plants. Biotransformation by unpurified microbial enzymes has the advantage of low cost and is a preferred method for production of natural compounds. This study isolated a strain of Rhizopus oryzae that could produce β -glucosidase, which efficiently hydrolyzes sophoricoside into genistein, from an enrichment culture of the dried fruits of Sophora japonica . After the composition of enzyme-producing medium and biotransformation conditions were optimized, a genistein yield of 85.6% was obtained after 24 h in a shake-flask biotransformation at pH 7.0 using an initial substrate concentration of 1 g/L. The developed process provides an alternative method for production of genistein, and would be suitable for scale-up production in the pharmaceutical industry.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 14
·10191-10203
·
IF 3.442
Yu Han,Chen Fenghua,Ye Li,Zhou Heng,Zhao Tong
Ion co-doped photocatalysts with In 2 O 3 /TiO 2 heterostructure (In 2 O 3 /TiO 2 (m)) were prepared through a new polymeric precursor method. The In 2 O 3 /TiO 2 (m) precursor solution is of salient advantage in coating photocatalysts on various substrates and multiple modifications. The photocatalysts were facilely obtained after the calcination of precursors. Mass ratio of In/Ti was optimized according to their photocatalytic performances, and IT(m)-3 ( w In/Ti = 3%, modified by N, B co-doping) showed the best photocatalytic activity. The band gap was successfully narrowed to 2.37 eV, and In 2 O 3 /TiO 2 heterostructure was successfully constructed in the photocatalysts. Visible light absorption and separation of photoexcited carriers were significantly enhanced. Under visible light, NOX (20 mg/L in the water) was 100% photodegraded in 10 min, with 100% TOC removed in 25 min. The IT(m)-3-loaded quartz fabrics (ITQ) also showed excellent photocatalytic performance. The photocatalytic activity of ITQ was repeatable and stable in 45 rounds of recycle without centrifugation. Synergetic effect of heterostructure and element doping was considered contributing to the outstanding photocatalysis performance. The polymeric precursor method proposed in this work showed great potential in large-scale preparation and application of immobilized photocatalysts. The synergetic improvement through co-modifications showed its proper compatibility with modifications.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 13
·2905-2914
·
IF 3.286
Zou Bin,Chu Yanhong,Xia Jiaojiao
Acetylcholinesterase (AChE) biosensor technology is widely applied in the detection of organophosphate pesticides in agricultural production via the inhibition of AChE activity by organophosphates. However, the AChE electrode has some drawbacks, such as low stability and high overpotential. Combining the advantages of multiwalled carbon nanotubes (MWCNTs) and ionic liquids, we constructed a novel bienzyme electrode [Cl/iron porphyrin (FePP)-modified MWCNTs/AChE/glassy carbon electrode], which included AChE and mimetic oxidase FePP. In this electrode, FePP is covalently bound to the AChE carrier via ionic liquid for increased electrode sensitivity and stability. Under optimal conditions, this novel biosensor has a monocrotophos detection limit of 3.2 × 10 –11 mol/L and good recovery of 89–104%. After 5 weeks of storage at 4 °C, the oxidation current was 97.8% of its original value. The biosensor has high stability and sensitivity for monocrotophos detection and is a promising device for monitoring food safety.
The complete synthesis process of Cl/FePP–MWCNTs/AChE/GCE
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JOURNAL OF CLUSTER SCIENCE
·
2019
·Vol. 30
·期 4
·985-994
·
IF 2.125
Zhou Tong,Cheng Yan,Zhang Haiyuan,Wang Guixia
Titanium dioxide (TiO 2 ) as one of the most important biocompatible semiconductor nanomaterials, has been widely used as antibacterial agents. However, since it is only active under ultraviolet radiation, its application has been dramatically limited. Here, TiO 2 nanoparticle (NP)-Au nanocluster (NC)-graphene (TAG) nanocomposites were designed to improve the antibacterial activity of TiO 2 NPs under sunlight condition. Incorporation of Au NCs and graphene into TiO 2 NPs can significantly enhance the solar energy utilization efficiency and promote the electron–hole separation, leading to enhanced reactive oxygen species (ROS) production in TAG, as evidenced by dihydrorhodamine 123 and DCF assays. Bacterial growth inhibition assessments revealed that TAG nanocomposites possessed more potent antibacterial activity against both gram-negative Escherichia coli ( E. coli ) and gram-positive Staphylococcus aureus ( S. aureus ) bacteria than TiO 2 NPs alone. Scanning electron microscope images of bacteria further displayed that TAG could cause severe damage on the surface membrane structure of both E. coli and S. aureus bacteria. Intracellular ROS production, glutathione depletion, and lipid peroxidation of bacteria were found to be elicited by TAG, suggesting the molecular mechanism underlying their antibacterial activity is possibly based on oxidative stress.
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Microsystems & Nanoengineering
·
2019
·Vol. 5
·期 1
·1-12
·
IF 5.616
Sun Hao,Jia Yuan,Dong Hui,Fan Longxiang
Rapid on-site analysis of airborne trace metals has been heavily favored over traditional methodologies because air pollutants can be altered by environmental, behavioral, and social patterns at any given time and location. However, existing portable approaches are either not capable of performing integrated on-site analysis or not yet practically applicable. Exploiting graphene oxide (GO) in enhancing the analytical performance of paper-based colorimetric detection, for the first time, this paper reports the development of a practically useful portable system for accurate, sensitive on-site characterization of trace metals in ambient particulate matter (PM). The system consists of GO-nanosheet-coated paper devices, unmanned aerial vehicle multiaxial sampling, and cellphone-based colorimetric detection. The increased specific surface area and the homogeneity of color distribution from the coating of GO improves the accuracy and sensitivity of the assays. Additionally, by leveraging a Wi-Fi camera, a self-developed app and a sample pretreatment cartridge, metal in PM samples can be readily processed and characterized on-site within 30 min. The effects of chip geometric design, pH, reaction volume, and metal interference on detection results have been studied. The detection limits of the system were calibrated to be 16.6, 5.1, and 9.9 ng for metals Fe, Cu, and Ni, respectively, which are comparable to the detection limits of commercial inductively coupled plasma (ICP) instruments, thus making our portable system practically useful. Finally, the system was used for airborne trace-metal study at 6 locations in Fuzhou City (China), and the results obtained using our system demonstrated good agreement with those obtained by the ICP. The significance of our system in supplementing air pollution study and furthering research on rapid, accurate, on-site air toxicity assessment was demonstrated.
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